The Dreamcast was a wonderful console and the very first 128-Bit one. Homebrew development was possible without the need to modify hardware, which is the total opposite of current next generation consoles. Many of us wasted tons of CD-R’s to burn homebrew games, demos, applications or emulators, but those times are past!
A chinese company produces SD Adapters for Dreamcast. Connected to the serial port you can put .iso’s on a regular SD card and start them via DreamShell. The adapter itself is pretty much affordable for around 10-20 Euros including shipping; please do not pay more than that, as everything above the mentioned sum is an attempt to rip you off.
DCEric, a Dreamcast fanboy of the first hour and also partitally known in the scene for his support to various projects, recorded a couple of homebrew games and even shows an emulator running at last. The loading time is sometimes pretty harsh, but it works! The compatibilty with homebrew so far is overall great.