The Binding of Isaac: Eternal Edition - Eternal Isaac (Hardmode)
Since I already have Dead God in Rebirth I got myself to play the original Isaac again for a nostalgia trip after not really having played this game since 8 or 9 years ago. Back then I never actually went for Eternal God because it was simply too hard for me at the time, despite having played the flash version before Rebirth was released. It still is for the most part, but I feel like you have a higher chance of beating the game if you get good items or a lot of soul hearts at the start. I was told the IV Bag glitch still works, so I'll use that in the future if I end up getting one.
Very good RNG for a very first hardmode attempt. Everything went well and near the end I just decided to clear out most of the rooms to get items I didn't have in my collection yet. Not really doing it again for other characters unless I have another run like this going. Next time I do need to pay more attention to some eternal enemies though, especially the Goblins, Hosts and Seven Deadly Sins which like to bullet spam a lot.
Lastly, I figured that its better to only beat ??? on hardmode so you don't need to beat him again if you beat him on normal mode before. I'll do this with every other character after this.