The winners on 1MCoaL always were a bit more excitable than the smug brains on WWTBAM. One particular couple, whose names escape me, nailed the fifth and sixth words with something like four seconds left. Big time thunder for that one. Mike Klauss used to have the clip on his website.
If you must narrow it down to millionaires, my (likely unpopular, "that's not a real game show!") nod goes to Jon Kenney from the first "Pepsi Play For a Billion," with Robert "Bob-O" Essig's Super Millionaire win coming in a close second. Dollar for dollar, though, nothing tops Jamaican Rose on Treasure Hunt, winner of $50,000 and the gold medal in the game show host clean & jerk.