Of the non-remake ones I have tried 1, 4, 5, and 7. Only liked 4 and 7 and of those two 4 is leaps better. But I think I like the more action heavy and less horror focused RE-games
I have also played, Code Veronica and Resident Evil Revelations and I liked Revelations a bit as well even if I played it on one of my least favorite owned Nintendo systems, the 3DS.

Every remake I have tried so far is awesome however.

For me the best one was 4 on gamecube. I still consider it one of the best games ever made.
Honorable mentions for resident evil 1 and 2. It was a great time playing these in my youth, scary as hell playing it as a an 12 year old.
I also liked 5, perfect coop game back then. I did replay it solo a year ago and did not like it anymore. 6 i never really liked at all. I still want to play 7 and village in VR but unsure if i really want to do that. Especially 7. 4 Remake in VR was a perfect game for me.

This question is hard to answer, RE is one of those series that has many stellar games in it's lineup. But if I had to choose one, the original RE4 as I have played through that game probably more than any other game (except Diablo). However, the RE7, 2, 1, all follow closely behind.

I prefer the original re1 over the remake.  The remake is too dark, as in the color palette is just brown and blue. The original has color , imagery stays vivid in the mind long after instopped playing.  I think it was the first game that broke the idea that horror only comes in the dark.Remake was just too dim.  Lost the magic of the original. Beat way to enjoy it on ps5 is put the resolution to original and use the filter that matches the ps1, 

I was playing RE2 and RE3 when I was 8, I distinctly remember one time when I was 9 and I was alone at home when at the start of the night, a really heavy rain started pouring down and I decided to play RE3 with lights out... man I was scared as fuck lol.

By that time I couldn't understand a thing about english, but that was the usual experience, basically no game had brazilian portuguese support so when we played games we shared discoveries between friends and powered through it, we would try every combination of items to eventually move a bit foward, sometimes things were obvious sometimes we really got stuck, and I have so many good memories of playing games like that.

We even used to play some games in japanese, and that's how we first played RE3 on a friend's PC because it was the version we could find, it was harder not being able to memorize some names as english at least had the letters we were used to, but not THAT different as we wouldn't understand regardless lol.

I also remember when RE6 was about to be released, me and that friend with the PC decided to warm up some days before and I got my PS1 to his house, we played 2 and 3 there, he called his then GF to try RE3 so we could see her reaction to Nemesis as her first time, she was saying that wasn't scary because it looked "bad" but she was jump running into zombies with no concern and dying quick, she didn't care enough to be scared, she freaked out when Nemesis jumped out of the windown (we had already had the first encounter) and put down the controller, just a jump scare but no fear.

That's when I understood we have to care about the character not dying (or just that we don't fail as the player) to be tense about it, simply not caring one bit and walking away when you lose makes it so much easier to deal with lol. We were already a lot older by then but she was constantly scared about movies because she liked watching those, people that don't care about videogames really can't enjoy stuff like we do, like game music as well, the involvement of playing and caring about it makes our experience with it so much stronger.

****, I am old.

The first game because you didn't know what the hell was going on, and it was all new and fresh.

Super Mario 64 and RE 1 will always be the games that floored me the most from where gaming was, when I first saw and played them.