I’m a BIG fan of the Pokémon Trading Card Game, particularly when playing in-person against others. I haven’t met people interested in playing with me for a few years now, but I still collect the cards - love the adorable art, as well. The booster packs all come with codes to unlock cards in the online version, too, so you can play with others over the internet if you so desired! It’s even in mobile form now!
I’ve been collecting for years, so I have some particularly rare cards, though my rarest are all from back when Wizards of the Coast held the reigns of the game in the US. I’ve even got some of the original Shining cards!
I also sometimes collect and play Yu-Gi-Oh, but Yu-Goi-Oh has gotten overwhelming with the sheer number of new mechanics it brings since I hadn’t played seriously in over a decade. I’ve enjoyed Duel Links, which was already linked in the thread! I do wish it had a more physical link like PTCGO does with its card codes, though.
And I love Hearthstone! I’ve been a fan of the Warcraft series since Warcraft 3, and Hearthstone is a delight visually and tonally! Love the humor, and the fact that I can be Medivh and Khadgar, my favorite bird mages!!! Hearthstone is just good fun. It may seem simple, but there’s a nice opportunity for strategy involved.
Since you asked for a story, I have a silly Hearthstone anecdote for you. One of the Tavern Brawls - silly weekly shake-ups to match mechanics - was that you could choose 3 cards and your whole deck would be built of 10 of each of those 3. So I went with a Murloc Tidecaller, Grimscale Oracle, and Murloc Tidehunter. The Tidecaller gets stronger when you summon other murlocs after playing it, the Oracle boosts the strength of other murloc cards in play, and the Tidehunter summons another murloc when played - and they all cost very little mana to play. As you can imagine, this was a ridiculous, devastating zerg combination. It was frankly hilariously broken and I had a blast storming through so very many wins that week! I know there were so many other more brutally broken combinations people could have chosen for that brawl, but I just had so much fun with my ridiculous murloc spree.