So, I was kinda curious how many books Marvel and DC have published that have been reprinted by other companies. Usually, it's licensed stuff. Here's what I can think of off the top of my head:
DC:
Fafhrd and the Grey Mouser: The Cloud of Hate: Reprinted by Dark Horse, collects Fafhrd and the Grey Mouser #1-5
John Carter of Mars: Weird Worlds : Dark Horse, the John Carter feature from #1-7 of Weird World. (Complete, but lacking Tarzan Family #62-64 instalments.)
Edgar Rice Burroughs' Pellucidar: At the Earth's Core: Dark Horse, at least the Pellucidar features from WW #1-5.
The Shadow: Blood and Judgement: Dynamite, reprints The Shadow: Blood and Judgement #1-4
The Shadow: Masters Series Vol. 1-3: Dynamite, reprints the Andy Helfer Shadow series #1-19, Annuals 1 & 2.
Edgar Rice Burroughs' Tarzan: The Complete Joe Kubert Years Omnibus : Tarzan #207-235.
Marvel:
Conan the Barbarian/Red Sonja: Dark Horse, and way, way, way too many to name.
GI Joe: IDW has been reprinted the entire Marvel series in many different collections and formats.
Showcase Presents Doc Savage/ The Complete Curtis Archive: DC then Dynimite. Collect's Marvel's Curtis Magazine b&w series, #1-8. A rare Marvel book reprinted by DC.
John Carter of Mars: Warlord of Mars : Dark Horse, b&w reprints the entire Marvel series, #1-28, three annuals
Marada the She-Wolf: Titan Books, reprints material from Epic Magazine 10-12, repackaged before as Marvel Graphic Novel #21
The Shadow: Hitler's Astrologer: Dynamite, again. This was Marvel Graphic Novel #35.
Tarzan: The Buscema Years Omnibus: Dynamite, Tarzan #259-287. May end up being vaporware, by the looks of the Amazon page.
Transformers/ Transformers UK: Ditto the GI Joe bit.