We went to Siem Reap for 3 days in early Dec. 2007. It was an awesome experience. Firstly we had great weather, it was dry and not too hot to be walking around the many temples. The crowds were manageable, though if you went in the opposite flow to the standard tourist, you missed out on even more of the tourist horde.
We flew to Siem Reap from Singapore via Jetstar Airways. The flight was very comfortable and got us into Cambodia by early morning, so the day was not wasted.
We were very lucky with the taxi driver who picked us up at the airport with his profeciency of the English Language and his charming demeanour. We decided that he would be our guide/ chauffeur/ 'man-about-town' for our 3 day tour. This man did not let us down and I very highly recommend him.
His name is MR. SOPHEAP (nickname is "TEE") and for approx. $30US per day, he will pick you up in his taxi, drive you to where you want to go, use his local knowledge to help you get the best out of your stay, and because of his excellent English, you can get an insight of what it is like to be a Cambodian living with a young family in 2007.
TEE's contact details are : [--]
Our itinerary included 3 temples (that was enough), a tour of the floating village (which I heartily recommend), a $10US Massage that was superb and some excellent Cambodian food from restaurants that TEE recommended to us.