Sorry, I couldn't come up with more accurate title for this thread. However; what inspired my intentions was a comment by Slam Bradley over on the "What Classic Comics Have You Purchased Lately" thread.
Slam writes of Murphy Anderson, that he didn't think he ever did worked for Marvel. I can't absolutely verify this (without wasting a good portion of my life without going through the Murphy Anderson entries at GCD, and even that might not settle it); however, I'd say Slam is correct on this.
I was wondering what other creators (artists and writers) we can can come up with who worked their entire career at one of the Big Two publishers at the expense of the other. (I know Anderson worked for non-Big Two publishers like Fiction House, but lets leave them out of this discussion).
Besides Anderson, I don't think Curt Sawn ever worked for Marvel, or Jim Aparo. I can throw out a few more names, but I'll see what other names people come up.
Who, other than Stan Lee, worked for Marvel, but never for DC?