Aight,so,I had this random Idea-
Ethgoesboom's Springtrap probably LOVES the Madness Combat series- I mean,watch at least any recent episode or one of the Incidents and you'll see what I mean.
His favorite characters would Probably be either Hank or Tricky,solely due to the carnage they cause

He would probably enjoy Newgrounds in general due to its humor and gore fest series.
(Pico's School,Madness Combat,etc)

He would probably like Happy Tree Friends for the same reasons-