I seriously rank RE2 right below REZero. It didn't really add anything new to the series. It was good but RE3 built upon everything with dodging, quick reaction things, quick 180 turns. It was solid and brought the series to the next level. RE2 didn't add much to the gameplay.

RE4 - Faster paced, more action,behind player camera view.
RECV - 3D enviornments, swinging Camera and non-linear gameplay
RE:0 - two people at the same time and gets rid of item boxes
RE - The original...there for it is original

What did RE2 do that was so much better than the above to add to the general gameplay of the series? I can't think of anything hence the low ranking.