I like Projekt. It's quick to configure and start using.
It has a clean interface and is easily customisable.
For personal IT small office IT use it is very much all you need to get started with tracking support and project statuses.
My favourite part of it was the fact that email worked seemlessly from the get-go. Make sure you have sendmail service available.
Keeping it simple makes it efficient. Summary tab gives you the quick overview for your day - that becomes invaluable.
Great work guys / gals.
An open, cross-platform journaling program.
A scientific plotting package.