For me, its a pretty close tie between Kanto and Hoenn, but i give Hoenn my vote:
The original starters are awesome, we all love them and care for them.
Hoenn though had some really cool starters as well, experimenting with new type combos like
Fire/Fighting, giving Mudkip a very solid type combo a well, and Sceptile simply looks awesome!
Plus, Blaziken is my all-time favorite Pokemon, so yeah