I would like to nominate the above fed, Hardkore World. I'm an active player there, and have been around since 2007.
I wouldn't nominate this place unless I really felt it deserved the accolade. It's not the flashiest fed, and you will quickly find that the shows are posted on a very slow moving schedule.
So why am I nominating it? Because as far as I can tell it's the longest lasting fed on the internet. I've seen a lot of feds, and none of them has the lineage this place has. In its current message board incarnation, it has been around since 2004. Whereas most feds close up shop within a year, this place has been plugging along for 6 years! But what truly makes Hardkore World unique is that technically its lineage goes back MUCH further than that...like, say the late 80's
. You see, Hardkore began as one of those play by mail fantasy wrestling leagues (you know, the kind that were advertised in the old mags and dirt sheets). Remarkably, we actually have title records from this time period. So depending on the belt you win, its possible your championship is actually older than you.
Hardkore has writers at a wide variety of talent levels. But the majority of the guys at the top of the card are genuinely the most entertaining I've ever read. I especially recommend reading stuff featuring Matthew X, Kilroy Evans, Lucifer Jones (who is no longer active) and Adrian Tanner, not to mention many others who get top marks for quality.
Now, I said earlier that the shows are infrequent (in some cases you have WEEKS to roleplay, and there is no roleplay cap). There's a good reason for the slow pace however: until very recently, the massive cards (shows average 15-20 matches PER CARD) have been written by one man alone. For that reason, Hardkore World shows are some of the most coherent and well written on the net. The guy in charge, Hardkore Jonnie Valentine, but in an obscene amount of time customizing each and every match to a character's unique personality and moveset. Seriously, read a show and be floored. As of late, due to changes in the man's real life, he has had to outsource some match writing duties, but the shows have remained flawlessly consistent.
Hardkore World also supports a unique region system. The fed kinda functions like the old NWA territories, but the regions are larger in scope. Hardkore America is the flagship region run by Jonnie Valentine, and we currently have another Japanese themed region. You are free to join either or both region. Also, if you're interested in starting a region under the Hardkore World banner (provided you have a proven track record) you have instant access to Hardkore World's large existing player base.
In short, give HKW a look and consider it for a top spot. It's pretty badass. Stick around for the off topic at least. We just recently had a thread go 4 pages in which we discussed the merits of one of the handlers eating a bacon sandwich given to him by a creepy neighbor.