Always was appeasing to see a familiar face return out of the shadows, even if some of the minor cast remained underutilized after their last installments it still was badass for those that did come back.
I MARKED OUT epically when Barry saved Jill in RE3 x.x
"Deathbed, redruM. I like to kill and have some fun." PSN: LatinChris_9990 / state you're a Gf's user before sending requests.
Out of the things you listed I'd have to say the characters. However, if it was completely down to me it would be gameplay as a whole. Each entry has never failed to impress me in terms of gameplay and quite frankly, the series has given me some of the most fun in regards to couch coop with a buddy.