i recommend riolu or munchlax. munchlax can learn metronome very early which is very useful. riolu evolved cant be poisoned and beats up most people that arent fire types. who ever you get, make sure it is supereffective against your partner. its ok if not but NEVER the other way around
munchlax set: water pulse thunderbolt metronome flamethrower
riolu set: aura sphere close combat force palm focus blast
riolu/lucario are in IQ group C. the best group in the game.
munchlax/snorlax are in IQ group G. pretty nice.