On PC the remaster no question. It'll have the most active playerbase with a few quality of life changes that you'll wish you had (like crushing stacks of souls).

As for playing Dark Souls 1 or 3, it's up to you. Mechanically 3 will be more familiar, while 1 will feel clunkier and more dated but in my opinion has a certain charm that the later games miss.

Honestly, you can play DS3 before DS1. Yeah, there is some lore stuff that won't hit as hard if you haven't played DS1, but it's not a requirement. If you're used to Elden Ring DS3 might be the easier game to get into. As for the Remaster vs. the original, I guess it comes down to how much you care about the multiplayer component since the Remaster probably has a larger player base.

Definitely the Remaster. I would go for DS1 first. Yes gameplay will feel odd but you‘ll get used to it. It‘s a fantastic introduction to the series and you‘ll see how much Fromsoftware learned and improved since then. Fair warning: DS1 might feel easier for you. DS3 on the other hand is more similar to ER.

I think the original has horrible controller support, but I haven't tried it in a long while. Just be aware of possible issues

Go for the remaster. If you were coming to the series blind I'd recommend starting with 3 (or even Elden Ring) but if you've already played ER I'd say go straight for Dark Souls 1.

Bloodborne

Dark Souls 1 is 100% worth playing. I won't be a purist and say that you need to play it before 3, because they're mostly standalone experiences... but you might miss a handful of references if you play 3 first.

As for how to play: if money's not a question, buy the remaster -- you'll get a better online experience that way.

If you're on a budget, however, you could simply Install the DSFix mod and start playing with the adaptive controller as-is. There's unfortunately no in-game rebinding UI, but you can still do remapping using either the Xbox Accessories app or directly in the Steam overlay (requires Steam to be in Big Picture mode).

My play order so far as been Elden Ring -> Sekiro -> Bloodborne -> currently playing DS1 remaster.

DS1 is definitely my least favorite so far, although it's not bad. Much much slower, and the challenge is in slogging through the levels with less challenging boss fights than later entries.