Pocket Planes and Tiny Tower are both awesome games developed by NimbleBit. They are really awesome pair, but unfortunately develop games for apple products. Tiny Tower and Pocket Planes are ported to Android by Mobage, and the ports are not the quality that the orriginal apple apps are.
The other big NimbleBit game is Pocket Frogs, which you make like. I'm a huge fan of both tiny tower and pocket planes, but never really got into pocket frogs. They also have a few other games. The only game so far that they have moved over to Android themselves is Sky Burger, but it is a very different type of game. I beta tested it, but my phone is really not fast enough to handle it.
I have yet to find another game I find as addictive as these two.