most of the ones on online-sweepstakes are legit. Any sites that look dodgie I avoid right away. I usually stick with name brand product pages. For the most part they will send you one junk mail to say they received your entry. These usually arent to bad. I just junk them right away. If any conest require you to click on email for verification I just skip them. Most of these sites for the larger prizes are legit. They wont spam you silly. Also if you get a link to eprize that is a legitimate company that handles the instant games for lots of companies. Alot of people have luck winning things like dvd's etc etc. I dont bother with those cause there are literally thousands of pages offering those prizes.

Roboform will save you lots of time. You can try it for free. Its especially good when you have a daily entry for several family members. Also its good when they have lots of questions. You can save the answers so one click to fill it in.