Samsung makes mostly Flash-based players, but I fell in love with their sound. This is even AFTER using a Creative. I've listened to iPods, but have never personally owned one, and I have to say they just cannot compare with Creative's, Samsung's, and other companies' machines. I have never considered purchasing one.
I currently use the P2, and the P3 has recently come out. They are great players, and I believe the P3, though flash, can get above 20GB of memory. There are also other higher-end players, but I don't know their model numbers.
anythingbutipod.com is a great website.