Depends. Slower desktop machines XFS.
Standard desktop XFS, if it has a smaller SSD, Btrfs.
Home server ext4/XFS + ZFS. Generic servers at work ext4/XFS, backup/storage servers ZFS.
Database server, experiment with ZFS with compression enabled - ratio 2:1, but encountered problems (probably a bad HBA model), standard ext4/XFS.
Hosts with virtualization, small server - XFS, big server - ZFS (technically a ZVOL).

Whatever my installation CD had as default 😂. I'm guessing ext4?

ext4, but the btrfs activity visible in the kernel changelog has slowed down recently after a long period of many bug fixes, so maybe I'll give it a try next time.

Pretty much all ext4 except for a few Windows installs on NTFS.

Btrfs for the compression and snapshots

ext4 because I value my data and don't want to lose it. I used to mess about with ZFS for mass storage but it's a university course to learn how to use and have decent performance.

I used to use XFS, but ext4 caught up.

And I used to use XFS... on something other than Linux.

Btrfs, but if I'd start from scratch today I'd go for bcachefs.

Xfs is solid Commenting b/c I'm disappointed no one else recommends

Btrfs on my Linux desktops and laptops, ZFS on my server, APFS on my Apple devices I guess

I tried exFAT for my USB stick but car sterio cannot read it.

Depends on the device and the use case, mostly FAT32, exFAT, NTFS, EXT4

Every photocopy machine I've come across that accept USB sticks do not support exFAT, so what I would do with my USB stick is to split it into two partitions, one FAT32 and the rest exFAT.

Most of my drives are EXT4, but I started using BTRFS a couple years ago and will be using it on all new installs from now on. I really like being able to make snapshots and compression reduces the install size quite a bit.

NTFS for the drive I had before jumping to Mint. Currently reporting several hundred gigabytes free, but refusing to make any new files, because... I don't know. I'll deal with it after an upcoming move.

The OS / home SSD is ext4, and so is the fat loud hard disk I recently purchased through an entire month of fighting Amazon over gift cards.

EXT4 on PC, ZFS on my server and APFS on my mac