I liked Amplitube...v1...I mean, it's not an AMP, if that's what you're expecting...but, I had one picky dude comment that out of all of my Egtr tracks he really loved the tone of this ONE--it was an AMplitube custom built BF Fendery sound. Most of my tracks ARE real amps, damnit!

...anyway, point is, you can get decent stuff from it. WavesGTR sounded good. I've done good clips with one of those Line6 GuitarPorts.

None sound as good as a half way decent amp (even at low volume)...but, they were good enough that when my quick demos were inspired enough, I just kept them.