if you want clean water and the best beaches, go south to the less-travelled islands. If you are looking for gay life, stay in Pattaya. Its alleged "limited choice" does not take into consideration Hornet, Romeo, Blue'd and so on. It' s more suitable for couples but even then P and I do not feel as comfortable in Patong as in Pattaya.
In the good old days of the 90s, Phuket was the first Thai place I visited after Pattaya and even then, as a single traveller,I was dismayed by its empty bars .Our four visits in the past few years haven't changed my opinion.