I’ve chosen ext4 for all the filesystems except /tmp, for which I am using xfs, and /home, for which I am using jfs. I made /tmp really, really big and formatted it xfs because it is fast with big files, supposedly; thus I can have GIMP use /tmp for its tile caches, which can be quite large. I chose jfs for /home because I am a packrat and have enormous amounts of stuff in my personal account, and likely will need to expand that space; a jfs filesystem is very, very easy to expand.
(xfs originated at Silicon Graphics, and jfs at IBM. If Microsoft has a sense of humanity then perhaps there would be a Linux version of ntfs, so that we could come to appreciate its true advantages, but instead we are just thankful not to be using FAT.)