It’s hard to chose just one, but I’m tempted to say
Answered Prayers.
I have a definite preference for Seb Mckinnon’s art, with Rebecca Guay and Nils Hamm close favorites too. I’m slowly building up a collection of Seb foils (except for the rare cards that have never been released in foil, like the upcoming
Misty Rainforest or the Ugin’s Fate alternate
Grim Haruspex... Hopefully one day I’ll manage to get the lot signed (planned on doing so in March at a local con he was attending, but My girlfriend unfortunately was sick so I took care of her instead of attending)