Super Ghouls N Ghosts - The crossbow and green/gold armor upgrade will make the Red Devil your bitch.
Streets of Rage 2 - continuously jab enemies (by pressing the B button a second at a time, instead of mashing) to gain more points and completely incapacitate them.
- Well timed jump kicks will take care of most bosses. Especially if you have them backed against a wall (not offscreen).
Star Fox 64 - Locking on to and firing at a target that's in close proximity to others will grant you more points (which is really helpful in expert mode).
Donkey Kong 64 - When fighting K.Rool as Chunky, wait until Rool's groin matches up with Chunky's head before charging the primate punch.
- Do not save at Hideout Helm until you get all the banana medals, as doing so will lock out the medals, making 101% completion impossible (real dick move by Rare).
Call of Duty: Black Ops 3 - When playing "The Giant" in zombies mode, always leave at least one zombie alive by the end of a round to give yourself time to buy whatever you need. This can be made even easier by making the last zombie(s) crawlers (blowing off their legs with an explosive or a ray gun).
Ninja Gaiden 2 - When fighting The Archfiend in the Poisoned Blood segment, use a charged arrow to hit its head, then quickly auto aim the arrows at the orb on its chest to damage it. Do not manually aim, as it takes too much time.