What Pokemon should I choose for the start ?

Any....all three are great pokemon

It depends...

If you want To have a challenging Gym experience but have it easy through the elite 4, choose Torchic.

If you want easy Gyms but the elite 4 is hard, choose Treecko.

If you want medium challenge for both Gyms and elite 4, choose Mudkip.

Anybody. Just think about this:

To be honest, there are a lot of arguments about choosing "the best" starter. If you never noticed, there aint a best starter. The simple chain of Treecko beating Mudkip, Mudkip beating Torchic and Torchic beating Treecko is only the start of the argument, but the movepools each weild. Think about these things when choosing your starter:

What strengths rely on each?
What weak points does this one have?
How good of a movepool does this one have?

Mudkip is one of my favorites, when you evolve it into Marshtomp, you can resist Electric, but you now have 4x weakness to Grass, which is where Treecko/Grovyle/Sceptile comes in with Leaf Blade. Unless Treecko/Grovyle/Sceptile happens to be Paralyzed and you happen to have Substitue and Ice Beam, Swampert is done with Sceptile. But Swampert is still very good.

Treecko is excellent. He does pretty well in the beginning of the game, but he gets a big weakness: Flying, Ice, Fire and Bug. Now, you find these in the Battle Fronteir, a Gym Leader, or in the E4. However, if you Breed him, you can get his most famous move, Leech Seed. This destroys a lot, making him very useful.

Torchic is underused for some reason. People don't like him/her because it won't win at the First gym, evolve it into Combusken(Fire/Fighting), and he/she gets Double Kick, allowing it to hurt Roxanne's Rock types. Now Combusken gets Peck, which destroys Brawly, the 2nd Gym Leader(Fighting). Blaziken is famous for the Reversaken set, which is why he is my favorite, and why I choose him 80% of the time when I start a new game(but don't save) for the heck of it.

In short, each starter is Unique, and there is no best, but take into consideration these tips and choose it wisely.

I always choose Mudkip. Give him the right set and he can own everything.(The set is Curse, Earthquake, Ice Beam/Rock Slide, Rest. You have to breed for Curse.) In terms of usefulness, I would say Mudkip is the best to choose.

Torchic.

My opinion torchick

All of them are good, but I think you should start out with Treeko. He will help you to get to the other towns easier, because the first two gym leaders are rock-type and water-type.

Hey

I chose Torchic because it's evolves into a really good Pokemon, blaziken.

But I had a problem trying to catch a water type Pokemon that can learn surf so then I wished that I chose mudip.

And guess what happened after that I had a problem trying to catch a Pokemon that knows catch, so I wished I chose treeko.

But blaziken has the most powerful moves eg: overheat,fire blast,sky uppercut.

Hope this helps

C ya

Superjoegoal