I'll do a list of favorites as well as runner-ups. Not going to do a list of least favorites because there are very few Pokemon I dislike.
Bug: Volcarona
Runner-ups: Galvantula, Ledian, Yanmega, Heracross, Genesect, Leavanny, Scolipede, Armaldo
Dark: Hydreigon
Runner-ups: Weavile, Scrafty, Mandibuzz, Zoroark, Honchkrow, Absol, Umbreon, Spiritomb
Dragon: Haxorus
Runner-ups: Hydreigon, Reshiram, Zekrom, Kyurem, Palkia, Giratina, Noivern, Garchomp, Latias, Salamence, Kingdra, Dragonite, Mega Ampharos, Altaria, Dragalge, Mega Charizard X
Electric: Manectric
Runner-ups: Galvantula, Ampharos, Magnezone, Raikou, Zekrom, Luxray, Rotom, Zebstrika, Stunfisk, Thundurus, Dedenne, Lanturn
Fighting: Mienshao
Runner-ups: Keldeo, Cobalion, Terrakion, Virizion, Conkeldurr, Primeape, Hawlucha, Meloetta, Emboar, Gallade, Lucario, Infernape, Blaziken, Medicham, Breloom, Hitmolee, Hitmontop, Heracross, Chesnaught, Toxicroak
Fire: Infernape
Runner-ups: Reshiram, Delphox, Emboar, Blaziken, Talonflame, Volcanion, Volcarona, Chandelure, Victini, Magmortar, Ho-Oh, Moltres, Mega Charizard X
Flying: Sigilyph
Runner-ups: Unfezant, Braviary, Staraptor, Thundurus, Hawlucha, Noivern, Talonflame, Mandibuzz, Archeops, Swoobat, Shaymin-Sky, Togekiss, Honchkrow, Drifblim, Salamence, Altaria, Lugia, Ho-Oh, Delibird, Yanmega, Ledian, Dragonite, Moltres, Dodrio, Gliscor
Ghost: Chandelure
Runner-ups: Gengar, Mismagius, Aegislash, Trevenant, Gourgeist, Golurk, Jellicent, Giratina, Froslass, Rotom, Drifblim, Dusknoir
Grass: Lilligant
Runner-ups: Serperior, Whimsicott, Trevenant, Gourgeist, Chesnaught, Ferrothorn, Virzion, Amoonguss, Sawsbuck, Maractus, Leavanny, Shaymin, Leafeon, Roserade, Cradily, Breloom, Torterra, Sceptile, Venusaur, Bellossom
Ground: Garchomp
Runner-ups: Stunfisk, Golurk, Diggersby, Krookodile, Seismitoad, Excadrill, Gliscor, Hippowdon, Gastrodon, Swampert, Torterra, Claydol, Camerupt, Mamoswine, Sandslash
Ice: Weavile
Runner-ups: Glaceon, Avalugg, Aurorus, Kyurem, Cryogonal, Beartic, Vanilluxe, Froslass, Mamoswine, Walrein, Delibird, Smoochum, Dewgong
Normal: Braviary
Runner-ups: Diggersby, Meloetta, Sawsbuck, Cinccino, Audino, Unfezant, Stoutland, Patrat, Porygon-Z, Glameow, Lopunny, Staraptor, Zangoose, Slaking, Swellow, Dodrio, Smeargle, Blissey, Snorlax, Kangaskhan, Sentret, Ambipom
Poison: Roserade
Runner-ups: Dragalge, Scolipede, Garbodor, Amoonguss, Gengar, Venusaur, Toxicroak
Psychic: Gothitelle
Runner-ups: Meowstic, Delphox, Meloetta, Sigilyph, Swoobat, Musharna, Victini, Cresselia, Mesprit, Latias, Gallade, Metagross, Claydol, Medicham, Lugia, Smoochum, Mewtwo, Starmie, Slowbro, Alakazam
Rock: Archeops
Runner-ups: Diancie, Aurorus, Terrakion, Barbaracle, Carracosta, Armaldo, Cradily, Corsola,
Steel: Magnezone
Runner-ups: Klinklang, Ferrothorn, Aegislash, Genesect, Cobalion, Excadrill, Lucario, Empoleon, Metagross, Aggron, Mawile, Klefki
Water: Keldeo
Runner-ups: Jellicent, Starmie, Clawitzer, Greninja, Palkia, Alomomola, Carracosta, Seismitoad, Samurott, Manaphy, Gastrodon, Walrein, Milotic, Swampert, Suicune, Kingdra, Corsola, Slowbro, Lanturn, Lapras, Dewgong, Azumarill
Fairy: Sylveon
Runner-ups: Diancie, Xerneas, Klefki, Dedenne, Slurpuff, Aromatisse, Togekiss, Whimsicott, Mega Audino, Mawile, Azumarill, Mega Altaria, Florges