Personally, I feel Mint 8.04 is the best Linux distro out there. I see a version 9 has been released and will upgrade to it soon.
Mint 8.04
I have Mint, and I have brought all of my old computers back from the dead. No keys, No pirated software. Mint is stable and good for most needs. No virus threats to speak of. I recommend it highly.
Running Mint 9 64 bit version...no problems....