Welcome back! TW has changed a LOT in the past years, but its still a great game with lots of great players. Pry the two best known servers are Alienbase (alienbase.net) and Black Sun (blacksuntwgs.gotdns.org) hosted by River Rat and Vader, respectively. Theres lots of great up and coming servers out there too. All kinds of games are around to choose from, depending on what you're after. Theres plenty of low turn stockish games, highly modded unlims, and everything in between. If you're looking to brush up on your game knowledge and find out about some of the changes, check out http://www.tw-cabal.com it's by FAR the best TW info site out there, and should get you on the right track. Also, you should be warned that scripts are MUCH more common and powerful than they used to be. Some returning players adapt well to this change, and some don't. If it doesn't bother you, check out TWX at http://www.twxproxy.com, its a scripter's best friend!
Theres also a good selection of quality TWX scripts available for free at http://www.grimytrader.com. If scripting isn't your thing, theres still some games out there that don't allow scripting, so you can still play at a pace more like what you're used to. Look through the game rebangs forum, and it shouldn't be too hard to find a game you'll enjoy.