My absolute favorite project is a Scarf Hat combo. You knit a regular hat and then bind it off. At the bottom you pick up stitches on each side of the middle of the back and knit a scarf. Well two scarves :)
I am loving making cowls! I made one in two evenings while watching TV. Fingerless gloves are also good quickies for me as well. Cowls and scarfette/neckwarmers are great because they are both quick to make and don't use up much yarn.