Like s5, and that's just the tip of the iceberg. BSD had FFS, but replaced it with UFS (my personal favorite). Some people would argue that DFS was notably bad, but I'm not one of them. I think it was merely bad-ish. I've used far worse. LIF before it was booter only comes to mind, as well as Minix (some programs have compiler directives in their source named MINIX_BRAINDEAD for a reason).
On the PC front you have stuff like HPFS, HPFS2, NTFS and NTFS2 (which is called 5, but its really version 2), but those are actually good. VFAT is an extension of FAT16, but not quite FAT32 either. All of the FAT variants suck ass.
On the Mac front, you've got HFS, which, while not actually good, isn't actually BAD either. Filesystem metadata is kinda kickass, shame about the rest though. You've also got MFS, and MFS+. The + was actually better than the nonplus, but it wasn't terribly much better.
More agnostic, you've got stuff like the Rockridge FS which sucks painfully if you have to write a CD, but not as painfully as ISOFS. Then you've got Joliet which is like Fat32 but with some of the good bits broken.
Finally, there's CLASSIC, which was Novell's native filesystem before they switched to their current equally disgusting filesystem.
Poll
