Basically, on the scale of iconicness, the undeniably iconic ones are as follows:
This is the "show this to anyone and they'll tell you exactly who they are" tier.
This is the "We'll probably call them Princess/Zelda/Ash, but we know what they're from" tier.
Anything outside of this sees a notable drop, from what I've seen. That being said, there are some specific fringe cases.
Specifically:
- Many will recognize him, but not know his name, or even Street Fighter, but may recognize him as "a fighting game character." This is because Ryu himself has become an archetype.
- Punch-Out!! is in a weird spot here. The game is generally very well known here in the States, being roughly the same tier as Frogger. Like Frogger, Punch-Out!! gets referenced and parodied here quite a bit (like being referenced in shows like Family Guy, and having ESPN parody it in a segment promoting the Maywether/Pacquiao fight from a few years ago, to name a few). However, this has more to do with being associated with Mike Tyson than anything, and most wouldn't be able to name Little Mac outright. This is also very region-specific, being mostly notable in the US.