When EverQuest reigned king long before WoW, soloist proponents were booed away with a common message: "Go play a single player game, MMORPGs focus around grouping and solo content has no place here." Today, most MMOGs offer solo play but in such a way that progression is meaningful, but grouping is still encouraged for the best rewards.
The debate that the benefits from soloing outweigh those that come from grouping especially in the early to mid game holds merit, but many of us still want to solo from time to time. Even if the game is filled with hundreds if not thousands of other players because let's face it, sometimes people suck and we want to play on our own.
Which game provides the best solo experience, is it World of Warcraft, EverQuest II, Guild Wars, or none of the above?