Lego obsession in full swing

Well within a two weeks time I have bought eleven Lego sets, all are single vehicle sets. Four sets from a seller from Brick Link, five sets from eBay, and two from a local Wal-Mart. I still have one more set on the way from eBay so I don't have pictures of it yet. but here is a picture of my current purchases.

I just realized that most of my sets are yellow, I really love the construction sets and will have to get some more. but which ones?