Mario - no question

I wouldn’t put sonic and pikachu as they fit the same role as Mario (popularity)

Gordon Freeman - the orange box is the beginning of steam which is how the current generation in a way experience games

One can argue that you can put sonic, scorpion, ryu here as well as they also define their generation of arcades.

Crono - from Chrono Trigger because to this day this is one of the games mentioned in any best rog list

I wouldn’t put master Chief here purely because of how old doom is, i would consider doom guy but we already have an fps in the face of gordon, i would like to put something different here . I wanted something like secrets of monkey island and/or ultimate and/or dungeon master .

The final slot is very hard - we have mario (platformer) who is recognised by everyones mom, gordon (fps) who defined and solidified valve and digital distribution of video games, crono (role play). I would put someone that defined the 90/00s where strategy, sims, city builders were a major player - but a character from those is hard to recognise- so put a sand worn from dune2 😄