One of the most visually appealing countries in the world, Italy is more lovingly called as Belpaese or (Beautiful Country). Widely regarded as the birthplace of Western Culture, Italy has its distinct aura and grandeur. Its various attractions make it one of the top visited tourist countries in the world and it has the greatest number of UNESCO World Heritage Sites of any country. 

 (Source: lyng883)

The top destination here is Rome. No other city of the ancient world boasts of as much heritage and influence as Rome. The capital of the largest empire ever on Earth is  the embodiment of culture and royalty.The foremost attraction of this city is undoubtedly the Colosseum . The largest amphitheatre of its time was a symbol of strength of the Roman Empire.  A walk down its history is enjoyed by all. Next on head to the Roman Forum . This place is sandwiched between Palatine and Capitoline hills and is always a delightful visit. In the end do not forget to visit the grandest church of all and home of the pope-Saint  Peter's Basillica . This church is truly a visual delight with its giant dome being designed by the best artists of Italy including greats like Michealangelo .

 (Source: tellamfam)

Here is an excerpt from Wikipedia which sums up Rome beautifully:

Rome today is one of the most important tourist destinations of the world, due to the incalculable immensity of its archaeological and art treasures, as well as for the charm of its unique traditions, the beauty of its panoramic views, and the majesty of its magnificent "villas" (parks). Among the most significant resources: plenty of museums - (Capitoline Museums, the Vatican Museums, Galleria Borghese, and a great many others)aqueducts, fountains, churches, palaces, historical buildings, the monuments and ruins of the Roman Forum, and the Catacombs. Rome is the 3rd most visited city in the EU, after London and Paris, and receives an average of 7-10 million tourists a year, which sometimes doubles on holy years.

(Source:  Wikipedia, the free encyclopedia)

Milan is another top destination in Italy.This second most populous city of Italy is also known as the fashion capital of the world. A paradise for shopping, football, opera, and nightlife, Milan is a great city to visit.Start your trip with a visit to the majestic  Duomo or the Cathedral of Milan. This church is the seat of Arch-Bishop of Milan and took almost 500 years to build.Next up head on to the "Last Supper" which the famous masterpiece painted by Leonardo Da Vinci. And finally, Piazza Del Duomo will beautifully sum up Milan for you. This city square is located in the geographic centre of the city and is the artistic, cultural, and social centre of the city.

(Source: Alex [Fino] LA)

Lonely Planet provides an apt description oft the city:

At first glance, Milan (Milano) can appear like one of the models gracing its catwalks: great bone structure (in the shape of historic and striking new architecture), extravagant taste and no obvious soul. But Milans style and, yes, substance, are more than skin deep. Milan is the engine room of the country's economy and home of its stock exchange, yet it isnt driven by tourism. Treasures that survived WWII's extensive damage include its elaborate cathedral, Leonardo da Vinci's The Last Supper, La Scala opera house and Castello Sforzesco. What really sets Milan apart, though, is its creative streak

(Source:Lonely Planet)

France needs no introductions. A country which has been the top tourist destination of the world for well over twenty years, is undoubtedly one special place. The land of the finest food and wine is sure to woe you with its charm.

Located on the banks of River Seine, is the “city of lights”, Paris. The capital of France is synonymous with style and glamour.he city houses one of the finest museums in the world, the Louvre. This museum displays world famous artwork like Mona Lisa and  The Coronation of Napoleon. Apart from this Paris is also home to one of the most visited theme parks, Disneyland Paris.  Another thing which will woo your attention is the architectural elegance of Sainte-Chapelle, which is the most beautiful church in France.

 (Source: Ted Drake)

Wikitravel puts it beautifully:

Located in the north of the country on the river Seine, Paris has the reputation of being the most beautiful and romantic of all cities, brimming with historic associations and remaining vastly influential in the realms of culture, art, fashion, food and design. Dubbed the City of Light (la Ville Lumire) and Capital of Fashion, it is home to the world's finest and most luxurious fashion designers and cosmetics, such as Chanel, Christian Dior, Yves Saint-Laurent, Guerlain, Lancome, L'Oreal, Clarins, etc. A large part of the city, including the River Seine, is a UNESCO World Heritage Site.

(Source: Wikitravel)

Next up head to Marseille in South of France. The country's most well known port promises white sandy beaches and a perfect Mediterranean weather, The foremost attraction here is Notre Dame de la Garde chruch. It is one of most known landmarks of the city and one see the best of Romanesque-Byzantine style architecture.Continue your trip with a visit to Musee d'Archeologie Mediterranean or the Museum of Mediterranean Archeology. This 1863 museum is the oldest in the city and showcases many archaeological discoveries.

(Source: Marc DUPUY)

Here is an overview of the city:

Nestled between the sea and hills, Marseille is a surprising, seasonless and enthusiastic city. Founded 2600 years ago, the oldest city in France combines the richness of its unique heritage with a vibrant cultural life in one exceptional site. Sometimes endearing, sometimes rebellious, it loves to seduce the visitor who is rarely indifferent to the charm of its 111 districts, its mild climate and the mysteries of its gastronomy. As France's second largest city, Marseille recalls the values of sharing that have shaped its territory for centuries, maintaining in its name "Marseille" the memory of the ancient Greek from Asia Minor that participated in its founding. A port city with a strong identity, it has also managed to support the changes in time to become an unavoidable capital of the Mediterranean, open to the world.

 (Source: Marseille)

Located in the middle of the Alps is Switzerland. One of the most picturesque countries in the world, Swtizerland offers a mesmerizing experience. Its rich culture and biodiversity make it one of the most visited countries in the world. Start your trip with the magical city of Zurich which gives you a taste of the awesome experience of the Majestic Alps in Switzerland.

The largest city of the country has been consistently voted as the best city to live in. The city houses the famous Museum of Art or (Kunsthaus Zurich) which showcase a blend of western arts belonging to the 16th century and the modern works of painters like Pablo Picasso and Vincent Van Gough. The city is also the starting point of the famous Jungfraujoch –Top of Europe tour. This tour takes you to the unforgettable Alps Mountains where you experience the scenic beauty and picture perfect environment of Europe.

(Source: aanjhan)

Here is an insight into the city:

A fairytale city, Zurich is set on the banks of both a river and a lake, with the snow-topped Swiss Alps rising in the background. Clean cobblestone streets hug a hilly terrain and medieval church spires reach heavenward. Despite its reputation for being the center of old-school international banking and a capital for frou frou chocolate confections, Zurich is also a very modern city that chooses to meander coolly through life at an unhurried pace. Travelers desiring an authentic experience should strive to do the same.

 (Source: U.S. News Travel)

Another top city in Switzerland is Geneva. One of the major cities of the country , Geneva promises to be a great city to visit on any given day. Start your trip with a visit to magnificent Jet d'Eau. No body goes back from Geneva without visiting this fountain which projects140 meters into the air. Next up visit the majestic St. Peter's Cathedral which is the oldest and most grand of all churches in Switzerland.

 (Source: MZane)

Here is a description from Frommers:

Geneva wows at first glance. It sits in a prime Rhone Valley position at the southwestern corner of Lac Loman (Lake Geneva), within view of the pinnacle of the Mont Blanc. As you stroll through its cobbled old town, the pristine parks and promenades, you notice the cosmopolitan atmosphere is palpable. That's no surprise -- more than 200 international organizations are based here, including the European headquarters of the United Nations. The city's strong French influence shows itself everywhere: in mansard roofs, iron balconies, sidewalk cafes, and French signs.

(Source:  Frommer's)

The second most visited country in the world, Spain requires is the ideal choice to  sum up your European visit.This sun drenched country is located south to the majestic Pyrenees and houses glittering beaches , flamenco bailaors (dancers) , the famous tomatina festival and many other attractions.

The first stop on your visit to Spain should be the incredible city of Barcelona. A feast for the senses, Catalonia's capital has a distinctly Mediterranean feel coupled with a diverse range of attractions which will surely make you feel like coming back here again and again.The foremost attraction of Barcelona which is bound to leave you stunned is the Majestic Sagrada Famallia. This castle like church was designed by Antoni Gaudi in the 18th centuryApart from this magnificent piece of architecture one has to take a trip to the La Rambla street which connects the Plaça de Catalunya in the centre with the Christopher Columbus monument.

 (Source: Jsome1)

Here is a brief introduction to the city:

Barcelona is the place to go for people looking for a modern city with a strong sense of tradition, the most eccentric architecture ever designed, one of the world's greatest football teams, and unrivalled choice of options for eating, drinking and nightlife. As well as the constructions of Antoni Gaudi, Barcelona was home to Joan Miro, and the artistic scene acted as a magnet to the young Picasso both artists have museums dedicated to their works.

 (Source: Barcelona tourist guide)

Showcasing a perfect blend of culture and modernity, Madrid is one of the largest and most influential cities in the world.Start your trip with a visit to the majestic and brilliant Museo Del Prado or the Spanish Arts museum. This museum houses the finest European Art Collections along with some of the best work of sculptors.Next up is the magnificent Royal Palace of Madrid. This is a neoclassical wonder built in the 18th century and was a pillar of the erstwhile Spanish Empire. Breath-taking views of the city can be seen from here.Finally head to the Puerta Del Sol plaza which is the famous square of the city.  A favourite spot among the tourists and cultural hub of the city this place aptly sums up a visit to Madrid.

(Source: ChrisYunker)

Tripadvisor provides a great insight into the city

Strolling through Madrid is a great way to see the lavish Royal Palace, the 16th-century Puerta del Sol (Sun's Gate) marking the center of Spain, the old Moorish quarter of Moreria and much more. Art enthusiasts flock to the famous Prado, Thyssen-Bornemisza and Reina Sofia museums. Families enjoy boating in Retiro Park and visiting the zoo and the amusement park in Casa de Campo. After eating paella and tapas and watching flamenco, night owls can dance at clubs that are open until dawn.

 (Source: TripAdvisor)