I also think all the MSX systems have very cool designs. It's an interesting concept of cross hardware compatibility with an OS that spans different vendors (Microsoft) that doesn't get brought up that often.
The Mac IIs were nice. I like the Mac IIfx and the Original Mac II personally.
Bell and Howell Apple II:
Pretty much anything ever done by Frog Design was very stylish for its time. They did the Apple IIc, IIGS, Macintosh SE, almost the entire Mac II series, the Sun SPARCstation, the NeXT Cube, and Logitech's peripherals:
http://www.frogdesign.com/about/history/timeline.html#1984
The Cybernetic Mathputer. It's a childrens toy computer that taught math, 1975
The XOR s-4 was an s-100 computer in a compact case
I forgot how much I wanted an Amstrad PPC 640 when I first saw one also. Yet another cool retro but futuristic design to it.