Mudkip is kind of a cool Pokemon. I remember one of the adventure with a Mudkip that I was playing Sapphire and I had to go with my mum to work, but sit in the car. I pretty much sat in that car and played that game all day, and I only used a Mudkip (until it evolved). I'm pretty sure I made it up to Lavaridge Town, so I guess that's some sort of achievement. :)
Welcome to the community. :D Where you can check out anytime you like, but you can never leave! XD;
Now I'm just going to go off a whim and say your favourite Pokemon game is Ruby, for introducing you to Mudkip. My favourite game is probably Black at the moment, since it has awesome Pokemon, and introduced up to the almighty DERPFISH! You may call it Stunfisk, but I'm calling it what I want, since that's what it's name should really be. :P