I like #2 and #4 best as well. The diagonal lines of #2 is interesting. The look on the baby's face in #4 (and the way it makes you wonder what the baby is looking at) is also real interesting. Numbers 1 and 3 seem too vertical, centered, and static to me.

Before they made me they broke the mold!
http://home.roadrunner.com/~kflach/