I just picked up my 30GB White iPod 5G yesterday from the Apple Store. Its an awesome ipod and no question the best one by far. However, when I was watching Lost on it last night, I noticed there was one dead pixel in the middle of the screen.
I took it back to the store and actually had to argue a little bit before they let me exchange for another one. Seems like that should have been a no-brainer to return. They were saying that it wasn't significant enough but I thought that if on a 12" Powerbook screen 3 or 4 dead pixels would warrant a return, 1 would be enough on a small iPod screen.
Be sure to check your screens for dead pixels when you get your new ipods!