I've had a box at Serverbeach for a few years, and they've been very reliable, and are pretty cheap. There's been a single issue I was unhappy about, which was a mandatory IP change for my box due to a reconfiguration of their network (after they were bought by peer1, a fiber/bandwidth company).

All else has been nigh on perfect. They do expect that you'll handle everything yourself that can be handled remotely, though I wouldn't think that was a problem in this crowd. :)

Edit: Er, and if you do choose to go with them, email me for a discount code if you want one.

Cool - my brother uses Serverbeach and I've heard good things from him as well.

Oh, and I forgot to mention, Steve from Reddit.com was saying they've had a good experience with Server City, which will rent out fractions of a cabinet. I think they're based in Cambridge.