ilovemyumbreon
Holding a Moon Shard
Mudkip has a special place in my heart; I can't think of any other Pokémon I could share the new Hoenn experience with 
Does Waterfall even suck with the introduction of physical/special split?Mudkip. You can easily go through Rustboro Gym with it, since it learns Water Gun relatively early. Also, you can teach it Surf, which is one of the three HMs that don't suck (Fly and Strength are the other two), and that way you don't have to get yourself another Water-type slave. Also, Swampert is a beast in battle, having the highest base HP of the three starters, and some decent Attack and Defense stats, which cover up its low Speed. And it learns Earthquake by levelling up! How could I not love that evolutionary line!?
Torchic isn't getting a lot of love in the polls. :/
But I'm going to pick Torchic, as that was my starter in the original R/S/E games. It was also the first Pokémon that I had fully evolved by myself when I was younger. (Not including the bug types because those are way too easy to evolve.)