I use a variety of tools but mostly Nuendo ( http://www.steinberg.net/en/products/media_production ) for music and FX recording and multitracking. For all the quick and dirty loops, EQ’ing, Noise Reduction and editing I use Cool Edit Pro. It’s awesome.
If you do find a free editor a few things to look for is the ability to EQ…even a 10 band graphic EQ can help shape the tone, One that has some FX like reverb, delays and such and for me most important is is format changing abilities…being able to take a 16 bit wave and get it down to the 22k mono that the game engine knows and loves so much.
If you’re doing voice overs for ET I have a template made with the walkie talkie sounds in the begginning and end with static in the middle you can have. Also let me know if you need quick advice on how to make AM Radio or Walkie Talkie type tones with the voice.
Also I’m a moderator at www.audioforums.com where theres tens of thousands of users who can help. Cheers.