Flea Shampoo
One of the dirty little secrets of the flea industry is that you don't really need flea shampoo to kill the fleas on your pet. In fact, any shampoo will kill them because they mostly die from drowning. Nonetheless, it doesn't really hurt and if it can give you a slight advantage, why not?
For cats and kittens it is extremely important to use shampoo which intended for either cats or kittens, as the case might be. They are very touchy about it so don't screw around trying to use dog shampoo on a kitten or you'll likely end up with a dead cat. Don't come crying to me.
I can tell you right now that the people that sell it (pet shop people, Wal-Mart clerks, and even groomers) don't really know one from another and the truth is that there probably isn't much difference. Stick with a brand you've heard of and you'll be okay. (We use Sergeant's on our dogs and it works fine.)