I remember one having a warning for posting MMO Char to it's respectful topic , that which was also on a private server. GM Server is indeed one of them, since you will not have a chance of becoming a Blizzard employee -especially- if you're under 18. And even if you do become an employee, it doesn't make you a gm. Unless WoW's popularity drops below 1 million, you might have a chance.
-----
Anyway, why try many other mmorpgs where the only goal is to grind until you get bored or start pvping what is unbalanced and bugged in most cases ( in the free ones ) ?
I mean, World of Warcraft is still the top dog of any MMORPG you can find there.
Balanced PvP ( Though because of Arena, we are getting buffs and nerfs what not )
The real fun begins when you start PvE'ing though. 25-man raids ( once were 40-man, but set to 25-man so it takes less time to organize, buff, and stuff like that ) tactics and skills are more than required. Most of all, it is really fun, unless of course, the raid leader is some 10-year old kid screaming to Vent every now and then.
I've tried more than 10 mmorpgs and out of 2, rest were craptastic from the very beginning. The 2 i liked were Guild Wars and Lord of the Rings: online. Both were pretty fun, but Lotro is basicly only a gimped version of WoW with less players, therefore = less action, the class skills are pretty identical too. Guild Wars in the other hand, was pretty refreshing. I didn't play it for 'endgame pvp' or so since i tried it out on my friend's account.
So yeah, my point is : In the time you are searching for another mmorpg when you got bored to previous one. All the effort you put on free ones is stupid since they will never gain a huge success and usually have very low population ( soloing isn't fun in any mmorpg in my opinion at least ). If you play around 200 hours of all the mmorpgs there are that are free ( 10 hours of x and 100 hours of y, but still getting bored and keeping on searching ), You would already have a lvl 50-60 character in WoW.
PS. Sorry for the grammar , but i am really tired right now..