Back from my night class, and I feel I need to explain myself a bit.
Sales are CERTAINLY not everything. Not making sales is an issue, though. Sales in some aspect correlates to popularity and relevance.
When we look at 3rd Party characters. Who do we have and had have?
The original rival to
. The start of console wars on the level that we know them. One of the series most infamous of varying quality for titles game to game. However, still stands as a massively popular series with at least an addition to the list a year.
The face of Stealth. A series constantly referenced by the cardboard boxes and the iconic ! if nothing else.
Quite possibly the only video game character who could rival
to popularity. You can't really undersell the impact and iconicism of this guy.
Jump 'n' shoot man. "Megaman styled respawning enemies" is something that gamers just know. A series that's branched off into a vast number of spin-offf series which, effectively, all have been held with great reception and popularity amongst their fans.
Mr. Fighting Game. HADUKEN SHOYRUKEN are just things that go into common knowledge for gaming.
The JRPG that hit gaming the hardest frm the series that defined the genre the most. Arguably our most questionable 3rd Party newcomer and even still he is a prodigous child of Square.
There are very few gaming characters for 3rd Party that could be debated to be this impactful, and stay relevant. Banjo-Kazooie were bright stars of the N64 but largely have been lost to time since. Rayman, while having some good games, none of them have been that impactful for gaming.
The only MAJOR things missing, in my opinion, are Castlevania and Bomberman for the major games that have some amount of rememberable Nintendo ties. Then you look to something like Doom, Halo, or Minecraft for other things that made such massive splashes for gaming. Edit: the point being that those three, while impactful for history, have no major association with Nintendo.