ext3=ext2+journaling. So you don't really see any hit in speed.
I prefer ReiserFS, though I rarely get to use it for the sake that Mac OS X doesn't like it.
ALSO, do not forget a swap file if you have less than 1 GB RAM. Rule of thumb is:
-If you have less than 512MB physical RAM, make your swap partition double the size of how much physical RAM you have
-If you have MORE than 512MB physical RAM, make your swap partition the same size as the amount of RAM you have.
-If you have MORE than 1GB of physical RAM, you probably won't need swap, but it's never a bad idea to have one around anyways