Which one is better maple story or combat arms

This question can't be answered factually , not only because it's a matter of opinion , but because , those two games are completely different genres. Maple Story , ususally trys to target a younger audience , and is basically a 2D Platform/RPG. Combat Arms is a shooter. If you enjoy boh of these genres , here are a few other games you may enjoy. For now - www.gunz.ijji.com , www.crossfire.subagames.com , www.battleon.com
If you can afford MMOs , look for a GTA MMO In the Future. ;)