I second the Vox DA5. My favorite thing about it, and the reason I would choose it over a Microcube, is that you can open it up and put the adaptor inside of it. It also has a handy mic in, which allows you to sing and play at the same time. But I own both the Microcube and DA5, and could easily reccomend both of them. The Microcube wins in portability, because it is lighter, and it is much easier to work with AA rechargable batteries than AA rechargables plus 6 C-cell adaptors.
Both are great amps. If you need a little more power, any of the Roland Cube amps, like the 30 or 60, are also great. I love my cube 30, and it is the amp I play out of most. It is just loud enough for the bedroom, and maybe for a small venue.