I'd like to add Anode Heart and Monster Sanctuary to that fine list.

In my case, I enjoy marvel board games that bring out the characters' style a bit more than a skin on a good board game(already have plenty of good games). The already suggested Marvel Champions is a great coop where you play a single character trying to defeat the selected villain. I'll also put forth Marvel Legendary, it's a coop deckbuilder. If he has some favorite Marvel characters both of those games have oodles of expansions that you can mix and match.

Well, multiplayer was given so at least it's narrowed down to a buffet option for dinner.

With great suggestions like Hardspace, Unpacking, and Rain on your parade, I need to check out some of these others. Hardspace is on my Mt Rushmore of smaller games.