I have tried a bunch of different versions and landed on PC Engine CD, then realized it was also ported to PSX as part of the "R-Types" collection.
I've since bounced between these two versions a bit... PCE CD version feels really good to play but if there's too much on screen sprites start flickering out. PSX version seems to look very close to the arcade version (if not arcade perfect) but apparently it runs slightly faster. I definitely die more in this version. There's also the fact that R-Types is a PS1 game so there's little delays with memory card saves and loading screens, though I could get used to using save states to bypass all that.
I also kind of like the aesthetic of the PCE CD game... it's got a more vibrant palette, and to my eyes the 5X scaling of PC Engine sprites looks a bit nicer than similar quality sprites shown on the PSX core (I can get it close by messing with settings, though). In my opinion a lot of mid 80s arcade games have blander palettes than the ports that came later on 16-bit consoles. Especially PCE/TG-16 games. They tend to look super clean and vibrant. A case of limitations giving advantages some of the time, depending on preference.
Any preferences anyone wants to share? Is there another better version I don't know about? I think if it weren't for the sprite flicker I'd go PC Engine CD here, but it's annoying enough that I'm seeking alternatives.