Other Games Best Upgrade in a Game (No mods plz)

A lot of games have upgrades to weapons, armor, stats, anything really. Sometimes dlc may also add to that. Feel free to list your favorite game upgrades here! (dlc allowed, but unmodded games only please)

One of my favorites is the Jump Attack Lv.3 upgrade on Sly 3: Honor Among Thieves
with the triangle button, you can charge up an attack (spin attack and push attack too), pushing the triangle will charge it one level. There are 3 levels, level three is usually the strongest. Funny thing, I never unlocked Jump Attack Lv. 3 yet, but only Lv. 2 yet, but it should be better. Long story short, jump attack 2 (and probably 3) allow you to insta-kill rooftop guards. (rooftop guards are small guards that are your size who patrol rooftops and the grounds)

 

nice right huh huh

 

The Elf Cannon Next Level description thing fits this thread perfectly :P