Bad luck with mySQL?

For some reason mySQL runs like shit on every server I’ve ever used. I’ve tuned some of my servers mySQL setting but that didn’t seem to help. For some reason mySQL always times out (internal server error) and hogs resources whether I’m using cPanel, Virtualmin, etc. on Debian, CentOS, in US datacenter, in EU datacenter. Both my dual core and my quad core have these problems and my quad runs at 3.2GHZ. It is a Phenom II chip. Is there something I’m missing. Maybe I’m not tuning it correctly? You’d think if it’s just left on the default settings (which I usually do) it would work just fine.