1) PCE briefcase unit.
2 )Any Sony MSX2/2+, The Panasonic Turbo R, and the Sanyo Wavy PHC70-FD MSX computer (Along with the Sanyo Wavy 35). These are the best MSX2 and beyond machines. The Toshiba HX (pasopia) machines are amazing too. It's hard to pick just one MSX.
3) Famicom w/ FDS combination
4) Sega Master System (It's one of the coolest shapes for a system)
5) Sega Dreamcast