Any MMO that started Pay to Play and went Free to Play.
Probably holds the most truth, you know, since they first started with large funding during the development.
But when you say "developed" do you mean most stable, most content, unique features, etc? A lot of games that start off Free to Play usually start with the least amount of content, and grow as time goes on. For example, Runescape as you said, started many years ago and has had many years to grow upon its content.
Reputation: 10I would say Runescape is top also. It's been around for a long time and they update it decently. It's also very well populated which is always good.
allods does feel really smooth