Call for recommendations, from the tech savvy of you. Who has had a good experience with their web host?

At the moment we are on a shared hosting plan through MidPhase that looks and smells great, but the performance is not meeting our members' needs. Specifically, it is intermittently slow, and their sophomoric approach to defending DoS attacks is resulting in a lot of false positive blocked IPs for our legit users. While an upgrade to their dedicated server would fix the former, the latter would persist and is not acceptable.

A lot of the misc hosting plans I've seen are too stingy on storage and/or MySQL databases. We need many databases with beau coup volume to accommodate future plans where the whole site will be database driven.

Any suggestions?

Prefer recommendations of good places to go to, but identifying NO GO terrain is productive, too.

P.S. *nix w/ php 5 and MySQL 4.