Question: what are the best pokemon to catch in pokemon emerald?
Answer: Swampert: Obviously the best starter available in the game. ... 
Breloom: Shroomish helps a lot in the starting parts of the game. ... 
 Aggron: Realy strong Pokemon with high attack. ... 
Camerupt:I have put numel because there are no good fire types in the game and it is the best (until you obtain primal groudon)