hosting for drupal shops

I work for a small web design shop and we've got about 10 drupal sites under our belt. We love drupal, but it doesn't seem to play well with shared hosts. For example, the sites we're hosting on shared servers (hostway, godaddy and pair) run slower than we'd like them too.

Has anyone found a shared host which lets drupal be speedy (e.g., has fast mySQL) ?

We're also considering getting a dedicated server and putting 3-5 sites on it. Have any other web shops tried this arrangement or perhaps found a better one? Godaddy offers a dedicated server for about $120/month - has anyone used drupal with this arrangement?

So in short we're looking to host sites for companies + non-profits that a $300/month dedicated server is out of their price range, but $10-50/month would be acceptable.