One of the best there is is Typograf which can be found at www.neuber.com. If it needs to be absoluterly free, and you can live with an old 1999 beta, try 'the font thing': http://members.ozemail.com.au/~scef/tft.html.
Or, ask Alex to be a beta tester on his brainchild :)

Or google fontmanager +free