"FIERO is the feeling of TRIUMPH, of winning, of defeating a challenge, or overcoming adversity. People looking for that feeling are on the lookout for adversity – and they tend to want adversity where they can be partisan for their characters and the GM is actually playing against them a bit. If it's not a real challenge, with real dangers, then there's no payoff for a fiero-chaser. If you've ever died again, and again, in a computer game, and then finally manage to succeed, and felt a rush where you could stand on your chair and scream? That's fiero."
"NACHES is the enjoyment of seeing someone that you have taught, or are responsible for, go on to do well with that knowledge. If there's a player at your table who is always happy to teach the others about how things work, chances are they like their naches. Many GMs, unsurprisingly, get a lot of good naches and enjoy it. Some players can get this same kind of enjoyment from seeing a student or smaller ally of their character do well."
Read through them and see which are your favorite.
Perhaps you'll learn something about your gaming style, too.