1) T2 (you can watch this without seeing T1, but it definitely works better if you have seen T1)
2) T1
3) Salvation
4) Genysis (I loved Emilia Clarke as Sarah but the actor playing John not so much, and if they're going to re-create early scenes why not do them exactly like they were instead of way off)
5) Dark Fate (probably, haven't seen it)
6) T3
I think you pretty much nailed how I'd do it (and I have seen Dark Fate - it was pretty bad). I very much liked Bale's portrayal as John Connor. It's too bad it didn't do better, and we could've seen more of that direction for the franchise, instead of hitting 'reset' and going back to the same shit different smell. Genysis and Dark Fate were at least better than T3. That was just awful.
My take: I didn't hate any of them, but:
1. T2: Fantastic.
2. T1: Classic
3. T3: A MAJOR step down from the first two. But all in all, not bad.
-The rest: I don't care to rank them. They are all inferior, and they all make things unnecessarily confusing by retconning and/or ignoring something that came before. But none of them are
bad, and it's nice to get some decently-done Terminator nostalgia every now and then.