The simple Answer is, THERE ISN'T ONE!
There is a few guilds left still raiding on retail trying to re-capture that feeling of classic wow. Example would be "Screams of the Past" who is the last active large 60 guild out there, Who also just cleared MC with 3 level 60's in under 3 hours. YES THREE. Gratz to them but at the same time it also makes my point. You can not recreate the classic feel on retail. EVERYTHING has changed, Talents, mechanics, quests, shit even the raids themselves are too easy or are no longer in the game. If your looking to re-capture that classic feeling you had when you played classic or a new player wondering what classic is like, Forget it. Its gone, done and over on retail.
Well I was just wondering about PvP at 60. Well thats gone too. Since blizz put XP off players in their own bracket, and put 60's through 69's in the same bracket. Queue's won't pop. They could if the 60 community would rally together and try to centralize on one server/Battlegroup. Good luck with that, people can't afford the moves, don't want to, or in most cases think their server is the one that should be moved to. We tried this along time ago with "Luge crash Survivors" , "Rockin the nine set" and "Dirty." We all moved to Mal'ganis where Dirty was and it was great for awhile until blizz destroyed the brackets and shut us down.
So whats your option?
Private server. Hold on dick face before you get all crazy with me. A private server is the only thing close to that classic feel. A server like
Feenix Emerald Dream is blizzlike X1 rates with no donation crap. Its only here will you experience what classic is like because it IS classic wow. As we all know private server's are buggy. You will find pathing issues galore, Bugged quests and raid bosses. But its about 80% the classic wow feel opposed to the maybe 20% you get on retail, if that. So if the Classic experience is what your looking for, Roll on a private server. If your just looking to get gear really fast on a 60 and look like a classic raider, play retail. $15 a month for a 20% classic experience or free with some bugs for a near full classic experience. You pick.