For the first two nights in Phnom Penh, Cambodia, I stayed at The Last Home guest house on #21Eo, Street 172, in the backpacker area. I shared a room for about $20 a night which included an air conditioner but no wifi. I really liked my room. The Last Home is located in at the far end of the backpacker area which means it is a little quieter here. For your wifi needs, just visit a nearby coffee shop and/or bar.
You can get some good banana pancakes at the Arrow Bar (#3, Street 172), located hear The Last Home.
Some pictures below:
(The Last Home Guest house)
(View from the balcony, you can see the Arrow Bar from here)
(Street 172)
(Royal HiNess Hotel)