Humble has a pretty interesting bundle running right now, celebrating Jack Kirby and Will Eisner, who would both have turned 100 this year. It’s definitely an odd assortment of stuff. Most of Kirby’s work was, of course, work-for-hire, done for Marvel and DC, so none of that’s going to be in a bundle like this.
Eisner’s Spirit character was creator-owned (very unusual at the time). I think DC currently has the rights to reprint the original Spirit material, so none of that is in the bundle. Some modern Spirit comics, published by Dynamite, are in the bundle though. (DC published new Spirit stories for a while, a few years back, and I’ve read most of those. I haven’t read the newer Dynamite stuff.)
A couple of Eisner’s modern graphic novels are included, and those are all pretty good. (Of the two included, I’ve read one.)
For Kirby, there’s a couple of collections of his very old romance comics, plus some of his creator-owned stuff from the 80s (Silver Star). And some newer comics featuring his creator-owned characters, but done by other creators. I read the original Silver Star series when it first came out, and it’s pretty weird stuff. I haven’t read any of the modern spin-offs.
And there’s a bunch of magazines and books about Eisner and Kirby, including a bunch of stuff from TwoMorrows. So quite a random collection of stuff, of varying quality. But probably worth $15 or $20, given that some of that would be going to CBLDF and/or the Hero Initiative.
If you wanted to read a nice collection of Eisner’s original Spirit comics, Will Eisner’s The Spirit: A Celebration of 75 Years would be a good place to start. I was trying to think of something similar for Kirby, but I can’t really think of any one book that would be a good starting place. Maybe Fantastic Four Masterworks Vol. 1? Kirby did so much work for Marvel (and DC), it would be pretty hard to create a “best of” volume.