I hope this doesn't turn religious!
I happen to like (and have had good results with) DreamHost. DreamHost offers a number built-in "one click installs" for things like WordPress, dotProject, phpBB. It also can support perl, php, and Ruby on Rails.
The standard package includes "unlimited disk and bandwidth", although I suspect that there are practical limits for the low end hosted sites. The base package includes only email support, but that has been more than adequate in the past. The standard package is a shared Linux server. They offer Windows hosts and exclusive servers for more dough.
They did have a billing problem a while back, but they were upfront about it, made it right and haven't had any issues since.