ok, free stuff:
sound effects editor: Audcity. It's the one and only.
music creation: (ah the list goes on and on) ModTracker, Skale Tracker, Psycle Tracker, Fruty Loops demo (only restriction is you can't save your work, however compilation to mp3 is still enabled), Acid Pro demo (same as FL demo I
think
That's all I can remember
I use Audcity for sample editing and ModTracker for final mix, tho occasionaly I'll use Skale. I really want to learn how to use Psycle, but I just don't have the time. Remember, it's not the software, it's how good you are with working with the software
level editing: DeleD is my favorite, tho if you have UnrealED and know how to use it go with that instead.
BSP editing:er, lemme see.. Valve Hammer, Quark, andddd I think that's it
model editors: Wings3D is my favorite. Blender is *really* cool, but only if you are willing to learn the interface. I keep telling myself that I'm going to take a few hours and learn blender, but it never happens
That's probally a little more than you were looking for, but hey it may come in useful sometime
Everything I've listed I use (and like, except for the BSP editors. I don't like BSP, you see
.X shall rule the world!).