When viewing offers to complete, you are given 2 sorting options. The first is by type (100% Free, Trial, or Both), and is pretty self explanatory. The second sorting option is what I will be going into detail about.
Rating - This sorts the offers by their rate of approval. This is, to me, the most important factor.
Newest - Sorts by when the offer was posted to the site. Great if you'd done offers previously that hadn't confirmed and you don't want to re-do offers that don't work for you.
Payout - Sorts offers by their how much you get paid if you successfully complete the offer.
Cost - I always do just the 100% free offers, so I've never used this. But it sorts the trial offers by what you have to pay,
Name - Sorts the offers by name. If you go on the forum and see a lot of people having success with a particular offer, it's easy to sort by name to find that offer.