Depends what you want, whether you want compact, large memory space, robust. If you want compact Secure digital or XD. large memory XD, Compact flash, secure digital, robust all except Smart media. Smart media is old technology it is easily broken and has a max size of 512. XD is my choice but thne you have a very limited choice of camera fuji or olympus. For XD you'll need to be careful with card readers, difficult to find.