[JAHphoto]

I currently use a mix of Lightroom and CS3. Since I learned on film (3 years of film, only 1 and a half of digital so far) it really bugs me when I have to do a lot of post processing on my photos, so usually if a lot is required I just trash it.

Lightroom is a fantastic app, I love importing off my card using it instead of copying and pasting in windows. It's kind of slow, but I blame windows Vista, as it was much faster when I used XP. (currently run it on a AMD 64 X2 1.8ghz with a gig of ram, going to get 2, think that will help)
Lightroom really does all the editing I need, and more. CS3 is great, but I really only use it for HDR, I wouldn't have it if I couldn't get it for free.

Before lightroom came out I actually used a program called ACDsee Pro (version 8)
It was blazing fast, there was absolutely no loading time when scrolling through my 5D's JPG files. RAW was understandably slower, but still fast.
ACDsee had pretty decent editing, and had some effects that we kinda fun to play with.. but the effects were mostly useless for serious photography.
It was very simple to use, and clear. Photo editing program for people who want basic editing and don't want to spend hours learning how to use it.
I also used to use Paint.net which was a decent alternative to PS.. a lot like the GIMP.

Would highly suggest all of the above mentioned programs, Lighroom and CS3/2 if you can afford them, ACDsee if you want a simple fast editing program that doesn't break your wallet ($120 for the best version), and Paint.net or The GIMP if you want a decent free PS alternative.