I use PW's Fresh Color & Boost regularly. For B&W photos, which I only do if the colors are just awful, I use My4Hen's black & white actions that apparently are not for sale anymore. I can't seem to find them on her site.
That said, now that I've been looking, I think I'm going to pick up
Matchstick and
Color Wonder. You can get a free action if you like her FB fan page
here.