Dreamcast games are largely encription free. You can easily rip or download them. Not that I am saying to do that, because you can buy them for like $1. Look for the thead in hot deals, it has like 3000 posts.
In addition, you can get roms for all the games you already have, so youc an play games from almost any other system on it, from Gameboy, SMS, NES, SNES (Dream SNES > *) Genesis, PlayStation (though the emulator is slow) MAME, Turbograffix, and almost anything you can think of. The processor is insane on the thing, and can run Half Life with no problem. Yes, They made Half Life for the dreamcast. It was never officily released, but it is out there, and it rocks. It has Blue-Shift on it as well.
Not only that, but you can watch VCD's on it, surf the web (you can get keyboards for it from EB games for like $3 new, along with Nic adapters)
The best thing you can get for it is a VGA adapter. Holy God does that make a difference. I barely noticed a difference when running Half Life on my dreamcast or running it on my computer. Night and day difference.
There are about a billion racing games for the Dreamcast, and lots of fishcing games too (not my thing at all) hell, they even made a casting/fishing reel for it.
Games are cheap but exceedingly entertaining, controlers are like $5 (I have 9, 4 still in retail box), memory cards are like $2 (I have about 20) and rumble packs are basicly free. (I have 5 for when everyone comes over)
So basicly, you have system that costs about $30 and will play the ~250 dreamcast games, ~3000 or so NES games, ~1500 SNES games, and approximately eleventy billion more, with add on's that can be had for essentialy nothing, and a huge fan base that is bigger now then when the Dreamcast was actually out.