I like trophies better than achievements. The leveling system is pretty awesome, especially if sony implements unlockables at a certain level, such as exclusive demos, themes, etc. Or if you get the platnium trophy you get a discount on any expansion pack.
Granted achievements were the origin, inspiration, and basis of trophies. So they will always hold a special place. Thanks Microsoft for creating this, but Sony by being late was able to significantly improve on the design.
Fact: Earthbound is the greatest game ever made