Those arguing that WoW isnt the biggest and best out there are kidding themselves. You measure success in an industry whose sole purpose is to get people to pay to play your games by the amount of people paying to play it. End of. Your opinion might be there are better games out there, that money isnt the be all and and all. The games companies youre talking about as better? they dont agree with you, they would tear off a ball to have WoWs revenue.
Back on track, alternatives to WoW. Youve said new so I presume youve already taken into account SWTOR, which we can only hope is done right. For my picks for alternatives going now -
Rift - heard good things, borrowed a lot of successful mechanics from WoW, so may remind you of it! Same kind of setting as well so probably not.
LOTRO - great mmorpg, suffciently different from wow to feel fresh.
Fallen Earth - MMOFPS, probably at the limit of what can be done on todays connections. Kind of fun but the fps aspect feels a bit anaemic. (this is the major problem with MMOFPSs, weve been spoilt by the fluidity of 32 player maps which currently cannot be translated into an open ended world and it all comes off feeling a bit juddery and naff). Crafting and the like is pretty involving but quests/progress is a bit samey.
Darkfall - Fun for about 4 weeks until you get tired of getting ganked and all your stuff stolen / wearing your less than best stuff in order not to have high level players swat you and nick it. This was probably my second fave MMORPG because it was so unique to loot stuff that *should* be on the mob you just killed. The FPS was pretty good too but the world was empty, and those you did see were high level decked out PKs. Theres apparently one guy who does nothing but PK. Funny the first time, not so much the tenth.
For me (WoW player looking for something else) im lining up Minecraft (which looks very good - search yogcast in youtube for hilarity and to see gameplay - this will really test your love of gameplay over graphics) and a return to my old haunt WWIIOL. For simulated mass combat there really is no better out there, especially for propellor heads. Good Luck.