Mission J. Frog going out like a hero against Volgin.
Chip managed to beat No More Heroes 2: Desperate Struggle all the way through without dying. Especially impressive considering the amount of Nintendo Hard in the final boss, in which he was really expecting to not be able to get through in one try.
The ending of Metal Gear Solid 3, where Chip stops fighting The Boss until "Snake Eater" kicks in, at which point he dons the monkey mask and beats the shit out of her.
The entirety of the first boss battle in Metal Gear Rising: Revengeance, which involves Ironicus squealing in joy at the game, and Chip completely curbstomping RAY.
Later followed by Chip curbstomping Blade Wolf. And the Hammerhead. And every single other enemy. Chip turns that game inside-out.
During a follow-up video to the final part of the main campaign, Chip mentions that he fought the final boss five separate times, all of which were No-damage runs for at least the final phase, just to get the music cues he wanted for certain events. One example of many of just how much he strives for quality.
And then he did it again (Five times, over an hour and a half's work) for Armstrong's fight against Sam in the Jetstream DLC.