Hi, Richard.
I've been using Tamiya's Revo for a few years now, and I love it. I think it's only a grade or two up from the basic Spray Work compressor. It's very simple to use (just turn it on!), and it does everything I need it to do, from heavy coverage to fine detail spraying. It was my first compressor, and I've felt no need to upgrade yet.
I'm sure some of the more accomplished AB'ers out there could expound upon the virtues of pressure regulation and moisture traps and all that good stuff, but my ol' Revo has never left me wanting anything more.
I think it went for about 15,000 yen, or about 125 bucks US.
I'd recommend getting a decent airbrush, too.
Brian