I use ext4 on new desktop/laptop installations, and, of course, vfat for boot partition

(finally had to compile it in into the kernel, after 20 years of progress, a bit of irony here)
I have an older machines, with some partitions still reiserfs3, which I used widely in 2004-2013 (especially on /var and /home), and it stayed.
boot partition on non-UEFI machines are ext2
I also has a large storage disks, on which I use xfs
And now I have looked and saw that one my external drive is stuck at ext3