Soundwave on 19 July 2015
Improving doesn't necessarily guarantee better results either though.
The Dreamcast improved on the Saturn in several ways (easy to program for, 3D Sonic from launch, great 1st year roster of games, etc.).
The GameCube improved on the N64 in a lot of ways (easy to program for, optical disc format, third party games, Japanese RPGs, Resident Evil exclusivity, etc.).
