Pikachu's design is fairly simple, yet memorable. Even through all the generations, Pikachu just continues to remain relevant in some shape or form. I've seen a lot of Pikachu merchandise, art, and even this: https://www.youtube.com/watch?v=ycdcDFuGarM. Personally, Pikachu has remained one of my favorite Pokemon. Whenever I've had a chance in any mainline game, I would try to catch a Pikachu (and debate whether or not to evolve him/her into a Raichu later on). Pikachu's also one of my mains in Smash (even though he's one of the more complicated characters to master).