Interesting question.......for a fast satisfying project, I'd say Fiber Trends clogs are my fav. I like socks, but by the end of a pair I say I won't do any for a long time. Then, before I know it, I'm making more. Baby clothes are fun because they're quick and use a relatively small amt. of yarn. Sometimes I just want something to do so I make up a dishcloth. I guess it depends of my mood and the purpose of the knit. Not too thrilled with seaming, but I've made sweaters.
Pretty much, I've done it all.