Safeway has been having these type of contests for years now, but this is the first time I've really gotten into it. Currently they are holding their Lucky Break contest, with 3 ways to play:
1. Instant win
2. Online entry
3. Ballot entry
There are some cool prizes, like Hoover vacuums, Bulova watches, and Sharper Image speaker systems for the online game, Camcorders and luggage sets for the ballot entry, and a grand prize of a 2010 Nissan Rouge! So far I have won a Bulova watch, which is pretty exciting, since I've never won any of the Safeway contests before!!
You can get a ballot every time you shop at Safeway. There is also a no-purchase necessary option where you just swipe your Safeway club card at customer service and they'll give you a ballot (though a lot of the Customer Service reps don't seem to know about it). Good luck!