Although Pepsi, Mountain Dew and Jones run some great sweepstakes, the top of the pops has to be Coca Cola. Coke always has multiple sweepstakes running and the prizes are things people really want to win. MyCoke.com typically runs Text, Twist and Win sweepstakes. The entry forms are a little tricky, but if you follow the instructions, you'll do fine. The biggest, bestest Coke site, however, is MyCokeRewards.com aka MCR.
If you drink a lot of soda, you have no doubt noticed the codes in your bottle cp or on your multipack packaging. Save these codes! They are worth points at the MyCokeRewards.com site. You can accumulate lots of points when you drink soda, then use those points to enter various sweepstakes. The point value differ, but six points per sweepstakes entry is fairly typical. There are pages of available sweepstakes ranging from gift cards, to an iPod Touch, to a Royal Caribbean cruise.
Not a risk taker? You may want to go right to the Rewards center. Store your points until you need them, then simply trade them in for the item you want. Sometimes there are zero point items (free!) available, so it is worth checking in frequently.
Probably the most popular section of the MyCokeRewards site is the Instant Win area. You can trade in points to enter these sweepstakes, or click on the Rules and look for the Alternate Entry link. The Alternate Entry link will give you up to five free entries per day. If you like Coca Cola, and sweepstakes, you should definitely pay a visit to MyCokeRewards.com.