Ok, this is a bit off the wall, but...
Scarves...because they are a lot quicker than sweaters and blankets, they can be so many different colors and can have so many patterns, they are very useful, and very visible.
Although....if I knew how to knit that cute little bunny toy, I might choose toys. An army of bunnies, bears, elephants, and such.
HMMMMM, this is a toughie.
It's a toss up between afghans and doilies.
I love making afghans, because I love the thought that something I've made is keeping someone warm.
On the other hand, I love making doilies. I love taking that thread and making something pretty and lacy, to jazz up the place.
I guess if I have to choose,
Definitely blankets, because they can be big for adults, small for babies, and you can make them odd shaped so they double up as a wrap.