linux - Which filesystem is appropriate for formatting an USB-stick and install an operation-system?

I have installed my linux-system on a USB-stick. That works well, I can use it on different computers. I used ext4 as filesystem and ask myself it this is the best choice. Which file-system is best for USB-sticks? A good filesystem should not destroy the flash-drive too fast. Additional activities to secure data-integrity might be good (I do an daily backup). Another criterion might be higher performance.