Well the only series that completely sticks out when the word RPG comes up is Final Fantasy. Those games are so good, and are defiantly the best RPGs of all time.
WoW is the best there is MMORPGs rule WoW wins with wonderful ways I personnally dislike zelda, but i know for sure others are addicted to it because they love it, i just don't like the that is all
The best 'old school' RPG is Final Fantasy VI, the best middle school RPG is Golden Sun 1 & 2 and the latest and greatest is any more FF from 11 and on.
WoW is ofcourse one of the best there is, if not the best. But on the old school turnbased action It´s either the famous oldschool FinalFantasy (1-5, haven't played them after that). My true favourite is Lufia for the super nintendo. Great storyline and just an allout great game, can play that forever.
I consider MMORPGs and RPGs on different planes altogether.
My favourite MMORPG is WoW, but the only other one Ive played is FFXI, so I dont have much to base it on.
The Final Fantasy series are probably the best RPG series, though Elder Scrolls are all great too. My favourite FF is FFIIX, probably because it was the first one I played.
If MMORPG's count i gotta say guild wars. Great graphics, Great story line, Always something to get you busy your never bored, Wide chooses of classes each class is so different, Huge world, Plus you don't have to worry about spawn campers
