A while ago I picked up this Yamaha CBX-T3, which is a cost reduced version of the Yamaha TG100 (minus the LED display). The TG100 was released at about the same time as the Roland SC-55 and obviously lost that battle, but although it’s true that the Roland product clearly sounds better based on my experience with them both, I still think the Yamaha is worth considering if you happen across one cheaply. It’s build quality is good, it’s compact, it’s easy to use, and if it was your first General MIDI experience then it would still rock your world when compared to FM synthesis. Compared to a SC-55, the sound it produces is muddy and electric guitar doesn’t really sound like electric guitar, but it doesn’t sound “bad”.

There’s more information about it here if you’re interested – there’s a YouTube clip included down the bottom which directly compares the TG100 and the SC-55 (sound only).

Something interesting it mentions is that the 'C/M' button is supposed to "partially" emulate the Roland MT-32 / CM. I'll have to give that a try and see how it sounds.