It's between RE4 and RE2 I guess for me.
I think RE4 probably shades it partly for being so ridiculously 'not-what-I-expected' and downright action packed, but I do remember finishing RE2 and thinking, 'Wow that was good...' only to discover I got to play it through AGAIN from a different perspective. Which was super-cool and a first for the time I believe.
The original gets cruelly overlooked too, and it's the only one I've actually replayed in all fairness. I like the feel of it more than the others in some respects, hence why I bought the GC remake when I saw it going for £4 the other day. Looking forward to checking that out.
Then there was 3 AKA Nemesis. Which was... alright? The whole point according to every usual OTT computer game mag preview seemed to be that Nemesis could show up at any point and kill you without warning, when in actual fact it was painfully obvious when he would. Oh look, there's loads of health and ammo. And the music has stopped. And there's a large square, empty arena up ahead.
He was a double hard bastard though. And it introduced the Mercenaries subgames which was good, and made RE4 doubly awesome upon completion.
I've yet to play Zero, Veronica and 5. Any good?
The gun games all suck obviously. Especially Survivor. GOD, that sucked...
So I reckon 4=2 > 1 >>3 >>>>>>>>>Survivor