It died out so I crunched numbers. I gave each map a starting value of 0. A "Yes" vote would add 1, a "No" subtract 1. A skip would subtract 0.1, I thought that was a good to weight it in.
So, sole loser is http://www.quaddicted.com/multiplayer/details.php?map=dm with a value of -7.6.
These maps got a rating of 3.0 so go try them:
http://www.quaddicted.com/multiplayer/details.php?map=aggressr
http://www.quaddicted.com/multiplayer/details.php?map=bsdm8
http://www.quaddicted.com/multiplayer/details.php?map=efdm10
http://www.quaddicted.com/multiplayer/details.php?map=fatal
http://www.quaddicted.com/multiplayer/details.php?map=impdm2
http://www.quaddicted.com/multiplayer/details.php?map=pdm4
http://www.quaddicted.com/multiplayer/details.php?map=pkeg2
http://www.quaddicted.com/multiplayer/details.php?map=pope4
http://www.quaddicted.com/multiplayer/details.php?map=ravage
http://www.quaddicted.com/multiplayer/details.php?map=safe1
http://www.quaddicted.com/multiplayer/details.php?map=useabuse
284 maps got a value >0. About 2000 one <0.
Tab delimited file is http://www.quaddicted.com/multiplayer/results_20100317
Ordered by score, this is the interesting one: http://www.quaddicted.com/multiplayer/results_orderedbyscore_20100317
Original votes: http://www.quaddicted.com/multiplayer/results_votes_20100317