I play tons of pay to play MMOs and to be honest I prefer them to free ones in a lot of respects.

There are plenty of players in most subscription based MMOs, and, on the whole, they are better behaved. Sure, you still have some griefers and idiots, but since you're paying to play, there seems to be less of them. In the free games, its so easy to get another account and just start over that people seem more willing to try to cheat or abuse the system.

There are some good free MMOs out there, true, but I do think that the quality of service, and content, in paid MMOs is hard to beat.