This thread went complete opposite direction I expected, when I think perks, I think anything that can't really be bought, so things like good salary, ot rate, and a gym membership don't really count since they're all essentially money equivalents. Especially for FIRE crowds, money is plentiful, and already more than enough to meet your needs.
Perks in my mind are things that money can't really buy, since you can get money or money equivalents from a hundred different sources. Things like access to private concerts (An old company I had relations to hired Van Halen + Tragically Hip), or getting to travel to super restricted countries like Turkmenistan, or super neat plces like Antarctica or space.