GBA -> GBA SP as best (added backlight and better portability)
some runner ups tho
Xbox 360 -> Xbox 360 S (fixed RROD and actually looked more sleek)
PS2 -> PS TWO and PS1 -> PS one (both major redesigns that looked really nice, even if the PS two was a top loader)
Worst?
Looks wise, probably the PS3 super slim, or the Wii Mini which also removed some BC, multiple other features, and looks bad.
think i'll go with the Wii Mini