Nowhere near as much fun since they closed demonoid down. That was a great source for hard to find, out of print, etc.
KAT (kick ass torrents) is also now blocked in the UK as are one or two others. That was also a good site. Sometimes there are mirros that can be connected to, sometimes not. Seeing as how, according to unofficial information, Virgin Superhubs transmit a list of everything you do every 4 hours or so, they can keep an eye on the most popular sites. Though, as yet, there is no power to block each torrent site as and when they come across it . No doubt that power is on its way. The commercial, DRM obsessed Corporate sector has won the battle with legislatures. Any arguments in favour of fair use, the right to share, etc, have been bribed, sorry "lobbied" out of existence. Enjoy the "freedom" while it lasts, because it won't.
A good search resource is torrentz.eu - it searches torrent sites and presents you with a list of what it finds. This is more efficient than going for individual sites.