My favorite is Totodile. It's been my favorite forever, actually since I started playing the Pokemon Mystery Dungeon games.
When I was doing the test over and over trying to get Eevee I finally got tired and ended up with Totodile. I was like "Oh my God, this is SO hard!!"
After awhile Totodile became my favorite, and I wondered why I wanted Eevee, after seeing what moves it can learn.
When the next mystery dungeon game came out I was looking through Google, trying to find what answers got you Totodile.
Unfortanately my Totodile streak ended in Explorers of Sky. I got Skitty first and was like "Skitty's kinda rare, I'll keep it. I wish I got Totodile thoguh..."
Then when Heart Gold and Soul Silver came out I was like "I HAVE to get that! I NEED Totodile!" I eventually did and named my little Toto Croco, who is now a Feraligatr.
I'm definately looking forward to more Pokemon games, and more Totodile. That's my story of how Totodile became my favorite. ;D