I'm doing a "deathmarch NG, wearing shirt instead of armor"; and I try to complete a spreadsheet with the Gwent decks of every gwenting NPC (not by digging through the data, which seems like what smart people would do, but by playing even more Gwent than normally. Making them reveal the last missing card in my list is the hard part, particularly if it's a dupe of another card I already know. (and Stjepan is a cheater with his 2 duped Etolian Aux Archers!))
I also think that I should head back occasionally to The Secret World, but somehow, every other game but Witcher series feels still just very bland. I thought that would've been better after the latest playthrough, but nope.