Since the old DEMONOID shut down. Up until recently I have only been on IPT. Definitely a good site. There is a lot of stuff on IPT probably like most sites but I have never had an issue. Seed you earn bonus points to purchase upload credit. Donate and you get more upload credit and immune to hit and runs. There is a lot of crap going on behind the scenes but I try not to get too caught up with it.
I just recently got in TORRENTLEECH (thanks emiralem for invite) and I have to say its a good site but I am not impressed. There is no benefit at TL unless you have a seedbox. Seeding is hard and You need a seedbox just to not get banned. Of course you can donate but even that won't save you after it expires if you don't keep up with seeding. Speeds are similar than what I'm use to. It should be a bit easier when you contribute. I will use it as my secondary site. I have been hearing a lot of good things about SCENEACCESS and PTP. Never been a member so I can't really rate them but hopefully someday for my own opinion.