How has no one mentioned Taillow for top?
Gets Wing Attack ridiculously early, it's fast and hits hard too. It's a little squishy, but that is more than made up for. It wrecks Brawly, and holds its own against the majority of other Gym leaders. Imo, it's a lot better than Wingull for a flying type.
I agree with Blaziken/Swampert for top. Then can cruise through the whole game pretty much on their own if they want to. I'd say Electrike High... Only because it doesn't get Spark for ages, but it does wreck 2 whole gyms and an E4 member on its own.
I'm on a mission to train every Pokemon Family during a playthrough of 3rd to 5th Gen! Currently at: 532/602!
Current Team (White 2 [4 badges]): Vulpix/Zoroark/Mr Mime/Cherrim/Deerling/Marshtomp
Current Team (Black 2): Solrock/Emboar/Sunflora/Crobat/Dunsparce/Azumarill