Most populated is not always the best, particularly if you want to participate in our lovely new Hunt content. Excalibur is a cool place, all the Legacy players I know hang out there and they have some very interesting setups. Malboro's where I hang my hat, it gets pretty quiet off-hours but at peak it's certainly lively enough, and we muster enough meat puppets to keep Odin at a handy 59-61. Or if RP's more your thing you may want to look into Balmung.