Soundwave on 20 June 2015
Actually the funny thing is the best selling game systems for 3 of the 4 major platform providers (Sega, Nintendo, and Microsoft) came 4 years or less after their predacessor.
Sega Genesis - Launched 3 years after the Sega Master System (in North America)
Nintendo DS - Launched 3 1/2 years after the Game Boy Advance.
XBox 360 - Launched 4 years after the XBox.
Which kind of blows a (giant) hole in the entire theory.
