I don't really have a preference in terms of type for starters. For me, it's usually always been:

Kanto: Charmander, though Squirtle is dear in my heart

Johto: Cyndaquil / Chikorita

Never played Hoenn, but I guess Mudkip

Sinnoh: Liked them all! But I always first chose Turtwig. When I got platinum, I then used Diamond as my starter trade slave so my Platinum now has all of them.