Giant Guy wrote:
X-Tinction Agenda was great but that one more than the others was really well contained in 9 parts. I guess you can beef it up with the original Genosha issues from the 230s but otherwise it can't be turned into an Omnibus like Inferno or Fall of the Mutants.
X-Tinction still could go into an OHC considering the smaller size of some of the more recent ones. They could also include some of the lead-in issues like the Genosha story, and maybe the X-Factor Hodge issue(s). Actually, I felt Hodge was the worst part of that story. He just felt tacked-on and kind of unnecessary to me.

Fall could be a smallish omnibus. Some of the tie-ins were pretty solid. I remember the DD issue being particularly good. And who can forget the ubiquitous Hulk issue?