The one's done on rafflecopter allow you to earn more entries for doing certain activities. Most are simple, like, get 10 entries if you "like" these pages on facebook. Usually no more than 10, it's a very easy thing, and you can always unlike them later!
Some take a little longer, like getting 25 entries for commenting on the blog page. This requires a name, email, website (sometimes) and of course, the comment.
That said, I've run across quite a few that have gotten my attention. Some allow upwards of over 300 entries, and you can earn more everyday. Usually you can get extra entries if someone enters from your referral link.
Finally, there are plenty of Pin to Win giveaways. These are VERY easy, because they basically allow you to create an online wishlist by pinning what you really want. It also allows you to be social with it, because you're posting it to your board, seen by your followers.
Interested in signing up for some?
Here are a few blogs & sites that offer great giveaways!!
Want your blog listed? let me know!!