X-Men: The Dark Phoenix Saga Omnibus: collects Uncanny X-Men #97-105, #107-108, and #125-138, Phoenix: The Untold Story, Bizarre Adventures #27, What If? vol.1 #27, and a bunch of material from Classic X-Men.
Technically, this probably should have been called The Phoenix Saga, as it collects the entirety of the Jean-as-Phoenix storyline, but this is what'll sell. I mean, it's 70s X-Men. You don't need me to tell you this is good. It's some of the best comics work Marvel ever put out. Eleven issues of Dave Cockrum, followed by fourteen of John Byrne at the absolute height of his powers. This collection also includes The Untold Story, which is what issue #137 was originally would have been before Jim Shooter refused to allow the story to end with Jean alive after having destroyed the planet of the asparagus people, along with a roundtable interview with Shooter, Claremont, Byrne, and Terry Austin, explaining the history of the story and why it was changed at the last minute. There's a story from the Bizarre Adventures magazine where Jean's sister comes to terms with finding out Jean is A) a mutant and B) dead by remembering that time they got kidnapped by Attuma and turned into water breathers. (Comics, everybody!) What If? #27 is probably the most famous issue of the original series, which explores the ramifications of Phoenix surviving the battle with the Shi'ar. It's... not very good. Overall, this is a vital collection; my copy had a major printing error that severely fucked up issue #138 (Jean's funeral and Scott's departure), accidentally reprinting several pages of the issue before and some pages of Classic, but I'm not seeing this online as being much of a thing, so I may just have gotten a bum copy.
Captain Marvel: Ms. Marvel - A Hero Is Born Omnibus: collects Ms. Marvel #1-23, Marvel Team-Up #61-62 and #76-77, Defenders #57, Marvel Two-In-One #51, Avengers #200, Avengers Annual #10, Marvel Super-Heroes (the 1990 series) #10-11, Marvel Fanfare #24, and a few pages from various other Avengers issues. I.e., pretty much the entirety of Carol Danvers' career as Ms. Marvel the first time around.
What started as a naked attempt to hop on the 70s Women's Lib train several years after it left the station (the corner box on the cover has the words "This Female Fights Back!" in tiny print, and original writer Gerry Conway, who will gladly today concede he had no idea what he was doing, presents the Adventures of A Strong Independent Woman Who Doesn't Hate Men, Exactly, But Can Kick Your Ass While Making 73 Cents On The Dollar) gets a lot better when Chris Claremont, a writer who actually does have very definite ideas about how a strong female character should be written, takes over early on. On other words, it becomes a perfectly serviceable B-or-C-level Bronze Age Marvel comic. Most of his overwhelming Claremontisms are missing, as he's more concerned about writing a fun adventure book, not a soap opera with Important Things to Say. The art is chiefly handled by Jim Mooney with Joe Sinnott on inks, so it looks nice enough (Mooney was the guy you got if John Romita Sr. didn't pick up his phone) for the bulk of the book, with a couple of fill-ins by Carmine Infantino. Towards the end, the panic is setting in, and they try everything they can think of (a new costume, streamlining the cast, a change of setting), but it becomes clear the book is out of steam and it gets cancelled mid-storyline. Mike Vosburg is the artist of the last few issues, and it's some of the worst artwork I've ever seen. Afterwards, Carol makes a handful of appearances here and there (the MTIO is excellent, and features very early Frank Miller artwork), before her original storyline wraps up in the pages of Avengers, and specifically Avengers #200, which is heralded quite justly as one of the worst comic books Marvel ever put out. It looks nice (the art is by George Perez, at the point where he was becoming very recognizably George Perez), but the story hinges on the fact that (CW)
, presented by oblivious, tone-deaf creators who had no idea that there was anything wrong with any of that. Claremont came back for Avengers Annual #10 to explain why the Avengers, and the writers of #200, are stupid motherfuckers who are motherfucking stupid and JESUS CHRIST YOU GUYS; this is also the issue where Rogue, who up to this point only had the power to absorb powers and memories, holds onto Carol for too long and permanently takes her powers of flight, super strength, and invulnerability. (Michael Golden does the art here, and you either like him or you don't; I'm not especially keen on him.) After this, the collection skips over the whole time a powerless Carol hung out with the X-Men and eventually became Binary (presumably that's in Uncanny X-Men Omnibus vol. 3), only to wrap up with a story from Marvel Fanfare that calls back to the MTIO poker game and she finds out for the first time that Mar-Vell had died while she was off-world, and now she's Binary and look out, outer space, here she comes. Overall, a pretty representative slice of Bronze Age Marvel, more historically interesting because of what's happened with Carol in the last ten years than anything else.