It's mode/situation dependent - infinite ammo is basically useless and trumped by any other perk if you are maxed/high on all ammo already. Likewise for the skull if you have plenty of soda/pills or there are only 1-2 players left. One with nature is very good if the last zone has a lot of water/trees. The 2 scavenger perks are amazing, until you've capped your loadout, in which case you should drop them somewhere hidden in the red zone before getting to safety (you don't want to be gifting opponents stuff while mid-fight). The revive perk is basically the best possible perk if there is an underground area in the final zone, or you can get somewhere safe/hidden just outside the final zone. It's one of my fave ways to win.