I almost always choose the fire Pokemon. I'll list the starters according to region favorite to least favorite (Not favorite to least favorite region, favorite to least favorite Pokemon in each region).
Kanto - Charizard (5/5), Venusaur (4.9/5), Blastoise (4.8/5)
Johto - Typhlosion (4.8/5), Feraligator (4.6/5), Meganium (4.1/5)
Hoenn - Sceptile (4.8), Blaziken (4.6/5), Swampert (4.5/5)
Sinnoh - Infernape (5/5), Torterra (4.4/5), Empoleon (4/5)
Unova - Samurott (4.7/5), Emboar (4.3/5), Servine (4/5)