Been playing a lot of Magic: The Gathering Arena now that the open beta added the Guilds of Ravnica set. As digital card games go, this one has the benefit of being built on a card game system that has been around for decades and is tried and true. It plays so smoothly and quickly that it's easy to crank out a handful of games in an hour.
Compared to the titan Hearthstone, this one just has so much more nuance to me. Hearthstone's lack of phases and the fact you're only playing stuff on your turn just limited the whole experience.
Duelyst is probably my favorite of the popular digital card games because of the tactical board element, but I could see Magic: Arena surpassing it with enough playtime just because of how dang fast and elegant it plays without losing any of the gameplay nuance of the card games.
I could never connect with the fiddly nature of Gwent, although I heard they recently streamlined that game so maybe I'd enjoy it more now. At this point, I feel like that ship has sailed.
For a while I was curious about Valve's Artifact, but unless it ends up being some piece of brilliant design, I think it's going to be hard-pressed to compete with Magic: Arena for me. I don't particularly like the idea of stretching game resources over three boards. Same reason I felt like Gwent stunk because sometimes you just want to lose encounters while in Magic you're always trying to balance, bluff and feign a lot of different things.