This past April, I went to Thailand, Cambodia, and Indonesia. I was only in Bangkok so I cannot speak for other towns in Thailand. I absolutely loved Siem Reap. Its a smallish town with a very interesting gay presence. 3 bars in the main area and a few gay/gay friendly hotels. I stayed at the Golden Banana Boutique Hotel and it was wonderful. The staff was incredibly friendly and helpful to arrange things. Siem Reap, although relying heavily on tourism, doesn't feel especially touristy. It has somehow maintained its feeling of a small town in Cambodia. And all temples of Angkor make for a great balance from time lounging around the pool. The only difficulty with Siem Reap is that flights from BKK aren't cheap (only Bangkok Airways) flies direct...I paid around $300 USD.

My 5 days in Siem Reap was really magical, so I recommend it highly.