>>38593932If from Gen II, Togepi, thanks to the anime it's definitely one of the most recognized Pokemon to fans and the general public.
If from Gen III, if not Flygon or Salamence for the Charizard factor then perhaps Skitty, it strikes me as being in a similar position to Pikachu and has that cute sort of design that I think would work well in marketing.
For Gen IV I think Buizel would be a good pick, ignoring the edginess of Lucario and the unfortunate situation Buneary finds itself in being the pre-evolution to Lopunny, Buizel seems like the best candidate thanks to its combination of cute and cool in its design and being a very brightly coloured Pokemon which would make it easily recognizable.
For Gen V I'm inclined to agree with another anon that Minccino should be the rep although another option imo would be the Lillipup line, I think the Lillipup line very well represents the concepts of Pokemon what with loyalty between the trainer and Pokemon and given the general rule of thumb that a dog is a man's best friend I think you'd find an easier attachment for most people towards a Pokemon like Lillipup.
Gen VI is rather lacking for good choices, Floette wouldn't be a bad one, it's design is rather distinct and like Buizel from before it has a mix of Cool and Cute, other than that there isn't really another one in Gen VI outside of maybe Helioptile but I don't think people would find attachment towards it quite the same even though it has some good quirks to it.
Gen VII, hmm, well Stufful & Bewear would be bloody easy to market given they're already stuffed bear toys, otherwise I'd probably have to go with Rockruff, even though I hate Lycanroc Midnight's design I think Rockruff & Midday Lycanroc strike a good balance in their design that echoes how Pikachu & Raichu's designs compliment one another.