according to tirerack.com's user reviews dunlop m3 got the highest rating, followed by the m2. (last i checked about a month ago anyway..) m3 is an upgrade to the m2, so i'd say that's a good choice.
i heard blizzaks, due to the block tread design isn't all that great in the rain. i was ready to go and buy the m3s, but i couldn't secure the rims that i wanted, and decided to just drive my other car in the winter.. (i sort of regret that decision.. i miss driving my car..