If we're talking proper fugly then pretty much any 8-bit Commodore system ever made.
As for other Commodore systems, the Amiga 500 looked a mess what with its innards exposed with the floppy disk drive opening. The Amiga 600 looked toy-ish. Amiga CD32 looked ungainly but at least the CDTV and Amiga 1200 looked okay.
Moving onto other brands, this for me is by far the ugliest system I own,
The fact it has quite possibly the most useless and uncomfortable to use joypads I've ever had the misfortune to experience using (yes, even worse than the NES pad) makes it functionally appalling too, imho.
The red, green and blue keys of the Amstrad CPC464's keyboard looked garish too - not unlike its graphics it could be said!
On the subject of fugly consoles...
Pass the sick bucket already!
SNES looked like a Fisher Price toy, Mega Drive II looked nasty in comparison to the wonderful-looking Mega Drive, Xbox looked cumbersome and Game Gear just looked cheap and ugly.
Own: Jaguar JaguarCD Lynx 7800 Dreamcast Saturn MegaDrive MegaCD 32X Nomad GameGear PS3 PS PSP WiiU Wii GameCube N64 DS GBm GBA GBC GBP GB Virtual Boy Xbox Vectrex PCE Duo-R 3DO CDi CD32 GX4000 WonderSwan NGPC Gizmondo ColecoVision iPhone PC Mac