Hi,
Glad to hear from you again! I was just wondering if the Siem Reap itinerary suits or taste. Do let me know if you need some changes in that.
Phnom Penh definitely has a couple of places which you would want to do. Let me introduce you to the same :
The Royal Palace and the Silver Pagoda : constructed over a century ago to serve as the residence of the King of Cambodia. The Royal Palace complex and attached 'Silver Pagoda' compound consist of several buildings, structures and gardens. You can read more about all of it here 
Killing Fields : The Killing Fields were a number of sites in Cambodia where large numbers of people were killed and buried by the Khmer Rouge regime, during its rule of the country from 1975 to 1979, immediately after the end of the Vietnam War. Take a photo tour here
Tuol Sleng Genocide Museum : A genocide museum was established at Tuol Sleng after the 1979 Vietnamese invasion of Cambodia and today it appears precisely as it was left by the fleeing Khmer Rouge. The non-descript facade belies the horrors and trocities committed inside. A visit here is a visceral revisit of some horrible events, too much for some visitors. Read more here
National Museum : Located near the Royal Palace, Cambodia's National Museum offers a charming setting for a stunning collection of ancient Khmer art. Predominantly constructed of sandstone, the sculptures date from both the Angkorean and pre-Angkorean eras. Read more here
Wat Phnom : Atop an artificial hill built in the 15th century stands a stupa containing the ashes of a king from the same period. There is also a small Buddhist pagoda. Wat Phnom is a city landmark and a popular place for worship. Read more here
Russian Market : located away from normal tourist areas, but motodop drivers who cater to tourists will know it. Offers the opportunity to buy REAL designer clothes at a huge discount price. Read more here
