I use a Washburn Cheap-knockoff-from-thailand, and I don't use an amp. I use a Zoom PFX-9003 through my computer. ( http://www.zoom.co.jp/english/products/pfx9003/index.php )
The PFX-9003, which I have dubbed Mr.Zoom, is pretty amazing.
I'm glad that somebody started a thread like this, though, as I was thinking about buying a 7-string guitar and need further help to make a decision. Nowhere around here has one in stock that I can play around with, so I'm kinda leaning towards no. The one I was thinking about is the Schecter Damien 7.
As far as non-electric, I've got a 1969 Classical from Japan and a Crafter Half-size acoustic, which is a really nice guitar.