I always liked Beast of Gilfer from Yu-Gi-Oh, remember special ordering the shounen jump Archfiend of Gilfer when it was released to the actual CCG as a kid. Was so excited to get it. Not sure what even happened to all of my cards from back then but I had a great time playing that game with friends.
Had to resort to playing online games since then as all my friends stopped playing CCGs. Tried Master Duel last year but didn't enjoy a lot of the newer mechanics, it's like a completely new game!
My absolute favorite: Hearth of the Fluft. If you play this little fellow, all your current Poro cards in the game combine to Fluft of Poros. I use it in my Poro focused deck and if can buff your poros a little before, Fluft of Poros basically becomes the Exodia of LoR. My biggest accomplishment was a 46/46 Fluft of Poros card with way too many deadly keywords. Of course the Poro focused deck isn't the most successful but if it works out.. Oh boy it's hilarious 😁
My least favorite : Teemo. One of the weakest champion cards and he dies so easily.
I play commander, and one of my friends plays a Chulane deck. Fuck Chulane, can't deny his effectiveness.
I like Pot of Greed despite its confusing effect.