Nemo translated (in Italian, of course) an interesting comparison between the most diffused filesystems on Linux (and not only on The Penguin): Ext2/3, Reiserfs 3, XFS, JFS.
The original article was posted by hansivers on the Debian Administration Website.
Conclusion? XFS rulez!!!
And I'm on the same: I start to use XFS average 2 years ago... and some big partitions on my HD still demonstrate optimal performance.
Good Job, SGI!