We've been screwed over by 2 different hosts. I highly recommned that you DO NOT use:
When we were hit by the spammers last month, Ace not only shutdown our blog, but deleted our account and our files without any notice. We were not given a chance to retrieve our data and tech support refused to talk with me. Last year when spammers hit us Powweb would at least talk with me, but they made it clear that if we got hit again we would be permanently removed from the server.
A lot of bloggers are on http://www.hostmatters.com/. I've read a lot of good comments about them, and they seem willing to work with bloggers and the realities of the Internet. HM has had some weird problems in the past, but at least they weren't booting people off.
We shifted to dedicated hosting. BTW, Virtual Dedicted Hosting is not the same thing as the real thing. You are still sharing space with a bunch of other people you never met.