Another vote for Zen.
We have five Zen adsl lines. Best service I've ever had. The only ISP I recommend without any hesitation. Static IP and can ask for more too.
1 x swcomms line. It's okay, but relatively expensive.
1 x BE line. Bought before they would taken over by Sky, and so far it hasn't changed. Cheap, uncapped, fixed ip, good. If it breaks, or Sky get around to changing it to their system, I expect poor service.
2 x Talktalk lines. Dynamic, but incredibly cheap if you want line+adsl. Uncapped and I've had no complaints. Supplied modem is a bit pants, but you can fit your own. If you just want a pipe to squirt data along, it's okay.