To clarify, if I was introducing someone to the Diablo series for the first time and told them they’d have to start on the first one. I wouldn’t want them playing the bare vanilla version. There is a Bezelbub mod out there that gives the game lots of QoL improvements, you’d be thinking you’re playing a build of Diablo 2 before its final version.
So, if I had to tell anyone what the best way to play that game would be, it is the Bezelbub mod. That was how I’ve beaten the first game anyways.
Devil May Cry 3 sucks balls without the style switcher mod. Combat and combo routes feel so limited.
They eventually added a style switcher to the last re-release, but that’s stuck on the Switch. My recommendation will be to either play the Switch version or mod it on PC.
I personally don’t like the OG trilogy as much as DMC fans do, so I’d probably recommend DMC4 or 5 as an entry point anyway.