Just kinda asking because I discussed Pokemon related stuff with friends.Mostly because I am not a fan of the two newest
Anyway my favourite two Gens are 2 and 5, mostly because lots of content, Gen 5 had a great story and gen 2 the two Region mechanic.
As for favourite Pokemon characters:
Steven Stone, enjoyable Champ, liked his character and design a lot.
N is one of my all time favs, his morals, design, viewpoint of things, how he wants to change the world.
Silver and Blue should be appreciated as Rivals that are done well and still redeem themselves.
Hugh was a good mix between friendly and Douche Rival, Love his design.
Barry is a dufus but a funny dufus.
Misty is the only anime girl that travels with Ash I enjoy, same with Brock.
I also like Sabrina alot and how far she came from Gym leader to Pokestar actress.
Wally is a cinnamon role I wanna protect.
Cynthia is the best champ still to me.
Overall I think for me it's a hard tie between N and some of the other Rivals. The Rivals just impact your Journey so much.