Recently, found myself reading Grant Morrison's New X-Men, Joss Whedon's Astonishing X-Men, & the new New Mutants. A very disorienting experience, since the events in each occur during a different period over the past decade (2001, 2004, & 2009 respectively).
After being out of the X-Men loop for sometime (stopped reading shortly after the Claremont/Lee X-Men title debuted), found myself curious as to how the X-titles went from Morrison's New X-Men to the current Utopia base of operations. This train of thought quickly became a curiosity killed the cat endeavor.
Isolating not only what exactly to read, but when exactly the stories took place turned out to be a very frustrating experience. Could not find a single source which lists the individual collections of each X-title in chronological order. Marvel.com initially turned out to no help whatsoever. One would figure since they are in the business of selling comics, they would have a webpage dedicated to at least their in-print collections. You know, to let us consumers know what's out there...hmmm, maybe I'm just being picky.
Actually, a really helpful resource I was able to dig up was this list on Amazon.com. It is an annotated cross-title summary of the key story arcs, & a great point of reference.
wiki, as usual, turned out to be an invaluable resource too. Page I found summarized the key developments over the past decade to the point where I could've picked up any of the collections listed below and have some idea of what is going on. Really, could've stopped this whole process here.
However, my inner comic book collector wouldn't let it rest (we collectors do have OCD tendencies, don't we?). Utilizing wiki, Amazon.com, & eventually even Marvel.com, I began compiling a list of graphic novels for each X-title, using Grant Morrison's New X-Men as a starting point.
A tedious and arduous project for sure. With all the time and effort put into this, how could I not blog the below results? It ain't pretty, but it is a very comprehensive list of 21st century X-tiles to be found on one webpage. Essentially just focused on the team X-titles, so it isn't 100% complete. Also included a story arc timeline summary to help y'all gauge when exactly the collections take place.
First, here's a timeline summary of the major story arcs:
2001: E Is for Extinction
2004: Planet X, Here Comes Tomorrow, Gifted,
2005: House of M, Decimation
2005-2006: Deadly Genesis
2007: Endangered Species
2007-2008: Messiah Complex
2008: Divided We Stand
2008-2009: Manifest Destiny
2009: X-Infernus, Messiah War, Utopia, Nation X, Necrosha
2010: Second Coming
2011: Age of X, Schism
Now, the X-titles' Graphic Novels
X-Men
(note, title changes: New X-Men from issues 114-156, & X-Men Legacy beginning issue 208)
(issues 114-126)New X-Men Vol. 2
(127-141)New X-Men Vol. 3
(142-154)Day of the Atom
(157-165)Golgotha
(160-170)
(171-174)X-Men/Black Panther: Wild Kingdom
(175-176)Decimation: House of M - The Day After
(177-181)Blood of Apocalypse
(182-186)Super Novas
(188-199)
(200-204)Messiah CompleX
(205-207)Divided He Stands
(208-213)Sins of the Father
(213-216)Original Sin
(217-218)
(219-224)Utopia
(225-227)Emplate
(228-230)X-Necrosha
(231-234)2nd Coming
(235-237)
(238-241)Aftermath
(242-244, 248-249)Age of X
(245-247)Uncanny X-Men
(issues 410-415)Dominant Species
(416-420)Holy War
(421-427)The Draco
(428-434)She Lies with Angels
(437-441)
(435-436, 442-443, New X-Men 155-156)New Age: The End of History
(444-449)New Age: The Cruelest Cut
(450-454)New Age: On Ice
(455-461)
(462-465)New Age: End of Greys
(466-471)New Age: First Foursaken
(472-474)Rise and Fall of the Shiar Empire
(475-486)Extremists
(487-491)
(492-494)Divided We Stand
(495-499)Manifest Destiny
(500-503)Lovelorn
(504-507)Sisterhood
(508-512)
(513-514)Nation X
(515-522)2nd Coming
(523-525)Birth Generation Hope
(526-529)Astonishing X-Men
(issues 1-6)Dangerous
(7-12)Torn
(13-18)Unstoppable
(19-24)
(25-30)Exogenetic
(31-35)Xenogenesis
(mini-series 1-5)X-Force
(issues 1-6)Old Ghosts
(7-11)Not Forgotten
(12-13, 17-19)Messiah War
(14-16)
(mini-series 1-3)X-Necrosha
(21-25)2nd Coming
(26-28)Uncanny X-Force
(issues 1-4)Deathlok Nation
(5-7)X-Treme X-Men
(issues 1-9)Invasion
(10-18)Schism
(19-23, X-Pose 1-2)Mekanix
(Mekanix 1-5, X-Men Unlimited 36)
(25-30)Intifada
(24, 31-35)Storm - The Arena
(36-39)Prisoner Of Fire
(40-46)New X-Men
(issues 1-6)Academy X: Haunted
(7-11)Academy X: X-Posed
(12-15)Academy X: House of M
(16-19)Childhood's End v1
(20-23)
(24-27)Childhood's End v3
(28-32)Childhood's End v4
(33-36)Childhood's End v5
(37-43)Messiah CompleX
(44-46)X-Factor
(Note: numbering jumps from 50 to 200)
(issues 1-6)Life and Death Matters
(7-12)Many Lives of Madrox
(13-17)Heart of Ice
(18-24)Messiah CompleX
(25-27)
(28-32)Secret Invasion
(33-38)Time and a Half
(39-45)Overtime
(46-50)Invisible Woman Has Vanished
(200-203) 
(204-206)Happenings In Vegas
(207-212)Scar Tissue
(213-219)Excalibur
(Note: This series focuses on Xavier's & Magneto's attempt to rebuild Genosha, & has nothing to do w/ either the previous volume, nor New Excalibur titles)
(issues 1-4)Saturday Night Fever
(5-10)House of M: Prelude
(11-14)New Excalibur
(issues 1-7)Last Days of Camelot
(8-15)Battle for Eternity
(16-24)X-Men: Die By the Sword
(mini-series 1-5) (Note: mini-series to wrap up New Excalibur story threads)New Mutants
(issues 1-5)Necrosha
(6-11)2nd Coming
(12-14)Fall of the New Mutants
(15-20)Generation Hope
(issues 1-5)Limited Series
House of M
Decimation: X-Men - Son of M
X-Men: Deadly Genesis
New X-Men: Hellions
Civil War: X-Men
Happy Reading!
