RE4 was the first I played, borrowed it from a friend on PS2 and loved it so much to replay it many times, and even bought it on X360.
My favorite is RE5, an excellent game made even better by adding local co-op fir my wife and me to play together. We played through it several times.
RE6 we did not enjoy that much.
We just finished playing Revelations 2 together, it was OK, nothing spectacular.
I tried to play several older ones, Veronica on X360 and this latest remake on PS4 and I quit both within 30 minutes. The controls are horrible, camera sucks, I can't believe people used to play games like this, tedious, boring and slow.
I will definitely not play any if those other remakes they are planning, unless they decide to update it not to suck.