I think once we get into the 3D console area, the popularity contest gets a little more murky than the NES/SNES consoles. Those two are cross-generational in popularity, people I know my brother's age all kind-of dropped off precipitously on video games when N64/PS1 gained popularity.
For me, outside of some obvious timeless games, the N64's most important games are ones that require 4 people (Mariokart, Goldeneye, Bomberman, Smash Bros, Mario Party). I assume Nintendo wouldn't want to inflate the base price to pack-in 4 controllers, so I could see this being another mess like the NES classic where it's almost impossible to find spare controllers, assuming they even go the route of making it 4-player compatible.
PS1's library is mostly 1-2 player games, primarily because you had to buy an extra accessory to even enable 4 player games. In that sense, I think I actually see more value in a PS1 Classic because of that.