I like the hornady cam over collet style for more than a couple of bullets. Its one stroke, not 10 strikes on a concrete surface. And the bullets come out looking pretty much like they went in. Just remember to set it to the lightest tension that will get the bullet out and it puts very light marks on the bullet. Definitely re-useable. And the powder stays put. That is the part that I really like.
I love my cam lock bullet puller! I used to use the impact hammer type until I got sick of having a few damaged cases and bullets.
I use the RCBS cam lock model and couldn't be happier with it. Sure it's a few dollars more expensive, but you can get it on Midway for just a couple dollars more than the impact. I've had 0 damaged bullets and cases since I've started using it.
I don't like to be the only person who votes for it, but I'm much happier with the cam lock since I got it.
If you're only doing a case here and there, impact would probably benefit you the most since there is no time for setting up like the cam lock, but I completely messed up 39 reloads when I bought my cam lock puller, so I wanted something that was quick and easy.
Impact type- I've got one from RCBS that looks like a green hammer, and it works very well.