I dunno, but I like Meowth.
Amulet Coin + Pay day = Extra money~
Plus, Persian can use moves like Thunder and Hyper Beam.
All its normal moves may be crappy, but Technician makes them 1.5x more powerful!
Since Gen 5, There is now a 33.3% chance that Fury Swipes will hit 2 times, a 33.3% chance it will hit 3 times, a 16.7% chance it will hit 4 times, and a 16.7% chance it will hit 5 times. Ignoring the possibility of missing, it will hit 3.168 times on average, giving it an average power of 57.024... and then Technician boosts that up to 85.5.
Feint attack, then Fury Swipes and Quick Attack...
I'm not competing, but that Meowth can seriously levelgrind through wild pokemon.
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As far as 'Least Favorite Pokemon' - Probably Zubat and Tentecool.
Nothing against them attack-wise, but they were the only pokemon to actually make me yell in frustration at YET ANOTHER battle when I'm trying to get places with a low health party and no healing items.