Font Management Applications

Do you use some sort of Font management application through your workflow?

If so which ones do you consider the best?

I currently use suitcase which is bundled with font doctor and font book.
I like font doctors ability to convert windows TTF to mac fonts and vise a versa.
It goes even further to convert it to OTF.
Have used many different ones in the past but stuck to Extensis products for its stability during use.