Heh, this story could almost have written by me. It's the reason I held out so long on getting an LCD instead, and why I have my beloved Samsung CRT sitting still in the loft.
I was actually quite surprised that ZSNES at 640x480 fullscreen mode, whilst there is a small noticeable interpolation effect, looked quite good. Perfectly playable once you have the graphics being displayed... I almost forget I'm not on a CRT.
What has been a problem, though, is fast movement. This seems to be a problem inherent to LCDs. :-( Try emulating Sonic 1 (MegaDrive/Genesis) on a CRT vs an LCD. On the CRT, no problems. On the LCD, the rings in particular look fainter, and darker... well, everything seems to look a bit darker as you're running. I guess this is a small form of ghosting, and I don't think there's any way to get round it on an LCD. Any tips would be appreciated. But, I'd say that if you wanna play Sonic or the like, use a CRT.
By the way, I'm using an NEC MultiSync EA191M.