Roland GR-700: I once saw Mick Jones playing Prince's '1999' on one of these as an encore at a Big Audio Dynamite gig. At the end of the song, he threw it across the stage to be caught by a roadie. I thought that was really cool, and I didn't even realise it came in a flight case lined with pink fur!
Yamaha EZ-AG: Crap-looking midi headless acoustic guitar, with lights on the neck to show you what to play.
Roland GR-500:Almost the first Roland guitar synth, covered with knobs.
Casio DG-10: Comedy, spaceship-styled headless midi guitar, beloved of Electroclash groups a few years back.
Casio PG-310: Almost completely charmless 1987 strat clone, redeemed by a nifty little control panel. Built by the same company who make Ibanez guitars and Roland guitar synths.