Artist Gene Colan did so much exceptional work over so many years, its hard to believe it was one guy. He was also always much beloved within the industry.
I won't spend too much time eulogizing, but I will point you to this post pulling together thoughts from those working in comics, and this one from the AV Club which discusses Gene's career.
When I think of Gene, I think Marvel, which is funny because I know he did stuff all over the place. But he's in there with Buscema, Romita, etc.. one of the people who created modern comics.
We'll miss you, Mr. Colan.
Here's a link to Mr. Colan's official site.