http://pizzahut.eprize.net/fightnight/index.tbapp is a prize pack that could get you a trip to Vegas for a future fight and XBox 360 systems and games.
http://www.nflshop.com/sweepstakes/index.jsp is a link to numerous prizes sponsored by NFL Shop called the Super Dad Contest. You can win a new TV, furniture and games.
http://mlb.mlb.com/sponsors/sharp/sweeps/ is for a 46 inch Sharp LCD TV if you can predict the Player Of The Month for MLB.
http://contest.maxim.com/contest/streetbrawl/?cmp=Pontiac_ContestButton_Maxim is my personal fav, though I am not sure how much the wife would enjoy it. It's another trip to Vegas but this time it involves MMA fighter Gina Carano. They will throw in 3 nights, $2000 spending money, a helicopter tour, dinner and a show as well as, oh yeah, meeting Gina and being her guest/date for the MMA fight that night.
http://www.churchs.com/ufc.php is for you if you prefer UFC and could win you a trip to a fight in Vegas and/or numerous UFC merchandise and gaming stuff.
http://www.m2omedia.com/danpatrick/members/spend/raffles/raffles.jsp?rafflesid=30209&categoryid=0 is for listening to The Dan Patrick Show and it is a trip to the US Open at Bethpage Black including airfare, hotel and tickets.