If your looking for distortion, the line 6 amp farm is the way to go. Asfar as I'm concerned delay, modulation and reverb effects are basically all the same until you start spending some good cash. (I'm happy with my cakewalk fx)
I use DSP-FX AcousticVerb to add room ambience to my recordings. They also make many other "software" effects and all the reviews I've read are always great. Check out http://dspfx.com you can get seperate effects or a complete package.