I enjoy the Boomer, although with the respawn times, it can be annoying. I tend to puke then kamikaze instead of go and hide.
I enjoy using the Hunter the best, though. I find the Smoker can be a bit spotty with the tongue. Sometimes you get the person, then the tongue breaks for no reason. Other times, you are just out of range. The fact that a Smoker does no damage unless he fully constricts a person is lame too. The only awesome part about the Smoker is when you can pull someone over a ledge and then they suffer falling damage, or they hang onto the ledge and need help up.
The Hunter is awesome. Pounce on the straggler and make the whole group turn back, or pounce on one of them when they are all in a tight group, knocking the others back and getting a few good swings in before your shot.