I tried out Excadrill on my Black 2 team, and it did the job well for me. Mine actually has pretty neat Speed, I rolled a Naive nature and some good Speed IVs, and it's female.
I also used Lucario for the main story, but I had too heavy of a Fire/Ground weakness so I ended up replacing him with a Scrafty when I got to the post-game.
Chandelure was also fun to use, gotta love that 145 base Special Attack.