Test planning/documentation/management tools

Yes, we do run tests, but not nearly as many as I'd like !

I highly recommend TestLink - the list of tools that you linked to shows that it's had more downloads than all of the other tools put together.

I've used QualityCenter/TestDirectory for a long time.

I'm now using testlink and I must say that I prefer QualityCenter/TestDirectory by far, even if it based on some buggy ActiveX control.

QualityCenter/TestDirectory is more easier to use and the interface is quite better.

TestLink and QualityCenter/TestDirectory are mainly for manual test case (however, you can use Quick Test Pro on QualityCenter/TestDirectory to automatize your tests).

Fitnesse is another kind of tool in my mind : basically, you write your test case on a wiki and link that to a JUnit test. Another tools like that are GreenPepper, Concordion, etc.

You should definitely try out Klaros-Testmanagement http://www.klaros-testmanagement.com which has an free, unrestricted Community Edition.