The question isn't one of performance as much as it is warranty.
Kingston, Crucial, Corsair, OCZ, Geil, and other name brands almost always carry a lifetime warranty on all their memory.
Often you will see generic crap for sale that offers a "lifetime warranty", however getting them to replace your RAM is often an excercise in futility. The big boys all have good support systems and don't usually fight with you over RMA's. (I can personally vouch for Corsair and Crucial, they are great about replacing bad RAM).
Also, generic RAM is (generally speaking) less reliable and less compatible than name brands.