I tier-whored in Gen 1 so it was bulbasaur for me. Been avoiding fire for a few gens because they were all fire-fighting, rumors are that the new one will be fire-psychic though. But yeah, Fennekin looks like it has the biggest potential to look cool so thats for me.
To be fair though, it was really hard to not tier-whore gen 1(sans Yellow) due to the utter lack of anything that can deal with Rock & Water early on (the Electric resistance is cute too but doesn't matter against
Lt. Surge due to Sonic Boom spam). Once you hit Diglett Cave though and caught yourself a lucky level 29 Dugtrio you were set for the rest of the game (by the time Dugtrio stops being enough is when you should already have and finished raising Larpas/Snorlax/Gyarados/or something similarly asskicking). Additionally dealing with the first Mt. Moon and Rock Cave is really annoying without something that can oneshot Geodudes.