Tommy Lee Jones' most recognizable comic book movie role is his, let's say, spirited turn as Harvey Dent/Two-Face in Batman Forever but he has much more recently appeared in a Marvel movie - namely Captain America: The First Avenger as Colonel Chester Phillips, who worked with the super soldier-creating Strategic Scientific Reserve.
13. Josh Brolin
Josh Brolin likewise featured in a DC film, in the title role of the previously-mentioned Jonah Hex, before nailing a part with Marvel. He appears as the MCU's big bad Thanos who has popped up for cameos in Avengers: Age of Ultron and Guardians of the Galaxy (the part was played by Damion Poitier in The Avengers).