>>12057371If you haven't already got your lead/partner, the most overpowered ones are:
Pikachu (Agility+Discharge)
Torchic (Mirror Move)
Treecko (Agility)
Vulpix (Imprison)
The most
fun ones are:
Munchlax (unfortunately demoted to partner only in Sky. VERY useful in T/D where you can Recycle TMs forever; you need to link Recycle for partner Pokemon)
Any water types to walk on water
For non-starters:
Chingling is REALLY good, especially since once you can change leaders, it is one of the few Pokemon who can learn Fast Friend (required to even have a chance of recruiting Kecleon)
Female Combee is nice for when it evolves. Vespiquen's Attack Order is a room clearer, and it gets Collector (+chance at defeated enemies dropping treasure)