The RAID type you pick is totally dependant on what you want it to do and the number of drives you have available, one isn't necessarily better (unless you have a large number of disks and a dedicated RAID controller).
GuRkHa:
Striping and RAID 0 (although RAID 0 isn't technically real RAID)- Total capacity of both disks combined, faster access, NO redundancy
RAID 1 and Mirroring - Slightly different to each other but generally they offer slightly better read times but only the capacity of half the volumes total. The important thing is redundancy, if one disk dies, you dont lose your data.
- Pea0n