Git Gud! 
Sound1
Hornet's dialogue hitting the Hollow Knight

Everything's Comin' Up Millhouse
Sound2
A clip of Millhouse looking on the bright side

Greetings and Salutations
sound3
"Hey bitches and bros and nonbinary hoes" from the skating anime

Coexistence
sound4
Bush describing how he believes man and fish can coexist peacefully

If at first you don't succeed
sound5
Kaiba from Yugioh blasting them with the blue eyes again

The come-back-and-kick-me whistle
sound6
Roger from American Dad beating Jeff for blowing a rape whistle