The word "best" is always in the eye of the beholder... and then there is the question of do you want a Sense ROM or one based on Android Open Source Project (AOSP)??? They are all really good... and yes, there might be a bug or two on each... but even the most recent patches for the Official TB ROM has a bug or two.
Personally I prefer Gingeritis (Sense ROM)... and CM7 (AOSP ROM)... all though there are many other ROMs out there... just click on the link in my signature below just to see some of the ROMs that are available.