Successful is a matter of perception from players, usually based on if they liked it or not. For companies it's based on money invested and time spent. For example when I worked at Cryptic Studios, the amount of monthly subs for Champions Online required to stay in the "green" (Aka successful with no lay off) was 55k. Now from a player point of view, mostly everyone that played Champions Online when it came out would say it was a huge let down and not successful. When in fact, the company made good profits. Enough to fund another game at least. So yeah there are quite a lot of successful MMOs out there, but the general opinion is that WoW is the only one when it's far from the truth. WAR, Aion, Rift, CO and even Star Trek Online are all successful MMOs (And many others).
A MMO that's had enough subscribers to make some kind of impact on the industry. I wouldn't say WoW is the only successful one either, but all of the ones you've listed have made a splash and faded badly. The last two have completely escaped my notice. Aion and Rift, right now, are still holding a good number of subscribers but like the rest of the recent MMOs, they haven't made much impact because regardless of what the developers said, they're the same old thing in a different box. I'm not sure there have been any MMOs breaking the mould since EVE to be honest. Perhaps City of Heroes? There is some light on the horizon, though. TERA, The Secret World, Guild Wars 2 and Planetside 2 should, hopefully, bring something new to the table with the budget to make it work.
It would have been better if the world was more open with less zoning and the voice overs carried through past the starting area The violence was awesome and un-paralled in any game