best - cranberry martini's at the aut bar in ann arbor, mi... . Not sure what made them so tasty, but I ended up wicked hung over the next day from slamming them down.

near best - white chocolate martini at n9ne in Chicago. sooooo much better than a normal chocolate martini (which I actually find quite nasty).

if this thread is about real (non-flavored) martinis only, then sorry, I can't help you. I stopped drinking those the day I discovered that you could make flavored ones!