Charizard is definitely my favorite. It's a pokemon that I always have on my team, at some point in the game. Charmander was the first pokemon I ever had, so I will always have that attachment to it. My favorite legendary is definitely Mewtwo. It's another pokemon I always have, if not on my team then I have it captured anyways. I know these both happen to be considered "popular" and sometimes "overrated", but they have and will always be my favorites.
Well, I'm usually just focused on my most favorite, but since this is a multiple choice, I'll post my top five.
1). Leafeon (Could still change, but will stay in this place for a long while. <3)
2). Umbreon (Need I say more? )
3). Luxray (Always had a soft spot for him. :3)
4). Persian (Kitty. =^^=)
5). Other Eeveelutions + Eevee (I just like them. )
My all time favorite was Charizard, till a few days ago. Then I watched all the pokemon movies in a marathon, and now my favorites are Mewtwo, Lucario, Charizard, and Darkrai. I also like Pidgeot and Ivysaur though.
I've noticed I like human-like pokemon, that can speak english, and are of serious & mysterious nature ^^
Porygon and its evolutions, no doubt. A shame they're so hard to get...
Charizard is cool, and Pidgey too. I still have to do a playthrough where I keep it from evolving... Maybe I'll try to beat the Elite Four with one!