I never got my Breloom to learn spore ripppppp xD
Breloom w/ Life Orb, Focus Sash, or Leftovers
Adamant Nature (+ATK -SpATK)
EV's: 252 ATK/216 Spd/40 HP
Mach Punch - This is an obvious one. STAB, Priority +1, Technician boost that makes it go from 40 base power to 80, this is probably Breloom's go-to move.
Bullet Seed - Also an obvious one. STAB, 2-5 times hit, and a Technician boost that raises one hit to 50. Two hits = 100+ base damage, five hits = 250+ base damage. It's amazing.
Thunder Punch/Stone Edge - Counters for Breloom's greatest weakness: Flying. Thunder Punch allows for coverage, 75 base damage and a chance to paralyze OR flinch. Stone Edge has a higher chance to critical hit, 100 base damage, but a lower reliability.
Spore/Sword's Dance - Spore is the most broken status inducing move, with 100% accuracy and it's nearly guaranteed to make the opponent sleep. Sword's Dance is more of a risky path to turn, but it's worth it once you manage to pull off one or two of these.