Ranking them:
7) Resident Evil 1: The granddaddy of the series and...it shows. Really shows. Not a bad game, but it hasn't aged well at all. I don't have that much to say on it, only that it's fine on its own, but overshadowed by its sequels and remake.
6) Outbreak: Outbreak is, in a strange way, the 'best' survival horror RE game, in as much that its scenarios always have you at a disadvantage. You're on a time limit, with very limited ammo, controlling average joes for the most part. However, it's stymied by its lack of any overarching story (bar inference of what order the scenarios occur in), and that it has the problem of being with AI that's unreliable.
5) Zero: Better than Outbreak in the sense that it's a main series game. However, I just don't like Zero that much, and it's down to one key thing - the items. The lack of any storage boxes means you have to either leave items behind, or constantly go back and forth to get them to where you have to be. RE games have generally been scarce on resources, but Zero's scarcity is based mostly on your limits of patience, before yelling "screw it, I'll leave the shotgun behind!" Which is a shame, because I feel the buddy system works quite well.
4) Code: Veronica: A better game than Zero, but Code: Veronica is in the realm of being average for me. It lacks the glaring flaws of Zero, and while a bit spin-offy, is more relevant to the plot than Outbreak, if only because it re-introduces Wesker. However, there's nothing really special about this game either. Every game on this list after C: V has something notable going for it. C: V is meerly an average Resident Evil game. Not good, not bad, just average.
3) Resident Evil 2: What's this, you ask? RE2? Don't you know that RE2 is the best pre-RE4 game in the series, or best game in the series, period? To which I say, "well, no, I don't." I think RE2 is a very good game, but not quite as good as the next two on this list. But make no mistake, it's a very solid game. Decent story, decent gameplay, there's the same game system (e.g. Leon A, then Claire B, or vice versa), Mr. X, etc. Resident Evil 2 is a very solid game, and there's nothing really holding it back. However, I don't think it's quite as good as...
2) Resident Evil 3: Nemesis: Yes, I think this is better than RE2. I think this because it takes the strengths of RE2, and improves them. Story is still decent. It probably does help that Jill is my favorite character in the series, and this game does a lot to solidify why. But I think RE3 works because it improves on RE2 in that:
a) You see far more of Raccoon City. It conveys the horror of the situation more effectively, and one feels far more vulnerable being out on the streets than in a police station for instance.
b) Nemesis is far deadlier and more intimidating than Mr. X, in both gameplay and lore. Helps that in RE3, he's specifically after Jill, whereas Mr. X attacks Leon/Claire because they happen to be in the wrong place at the wrong time.
c) RE2 had the save game system, as detailed above. However, RE3 does have variability in its gameplay in that events play out differently in what order you play them in. I feel this is a better approach to replay value.
The only nitpick I can give RE3 is that it does veer a bit more to the action end of the spectrum than RE2, but even RE2 was doing that when compared to RE1.
1) Resident Evil Remake: Holy shit, this is how you do a remake. You take the first game, improve it in every concievable way (that includes voice acting), and you make it scary as shit. Like, actually scary. And...yeah. I don't really have anything bad to say about this game. RE4 still takes the top spot, but this comes in at #2 without a doubt.