I would love to see some more Warbreaker art! I don't know what it is about that book, but I feel it might be one of my favorite.
Stormlight Archive of course is probably a big favorite of mine being so all-encompassing, but there's something intimate I feel with Warbreaker. Lightsong is definitely one of my all-time favorite Sanderson characters. I can't place my finger on it, but he just resonated a ton with me - and made it all that stronger when you find out his true past.