With X-Men: First Class hitting theaters everywhere this weekend, interest in the mutant heroes has rarely been so strong. The X-Men have long been a central focus of Marvel's publishing line, with countless ongoing series, crossovers and graphic novels to their name.

The real question is which stories are actually worth reading. We hope to help with that little conundrum. We've gathered a list of what we consider to be the 25 greatest X-Men stories of all time. This list is a mixture of full creative runs, specific story arcs, and isolated graphic novels. In general, we ignored solo and character-specific books, as well as spinoff franchises like Alpha Flight, in favor of projects that showcase the X-Men as a whole. For his part, Wolverine's best adventures are covered in a separate list, which you can read here. Let us know what your favorite X-Men stories are by posting in the comments section below.

Death Hunt

New Mutants Vol. 1 #18-31

Sometimes a new artist can completely change the way you look at a series. Chris Claremont's New Mutants run received an unexpected shakeup when Bill Sienkiewicz became the regular artist on the series. Sienkiewicz's heavily stylized, almost abstract art was a far cry from what readers were used to. But this new visual approach provided the book with just the spark it needed.The series grew darker with Sienkiewicz on board as Chris Claremont introduced new characters like Charles Xavier's crazed son, Legion. At times the two creators seemed to struggle to find a unified voice, with Claremont's verbose writing style clashing against Sienkiewicz's evocative imagery. But if never perfectly united, the duo delivered some memorable adventures starring a younger generation of mutant heroes.

House of M

House of M #1-8

Anyone complaining that the X-Men never interact with the rest of the Marvel Universe got their wish with House of M. One of the first major event books of the modern era, this crossover teamed the X-Men and the Avengers as they struggled to deal with an out-of-control Scarlet Witch and her less than helpful family members. Their efforts led to an alternate reality where mutants were the dominant race and Magneto's family reigned supreme. But just as quickly as it began, this world started to crumble, and the end result was one of the most devastating days in the history of the mutant race.Many alternate universe stories lack any sort of lasting impact on the characters in question. This is hardly a problem with House of M. The fallout of "no more mutants" continues to drive many of the X-books and ensures that life for mutants is more dangerous than ever. House of M also deserves credit for elevating Olivier Coipel's name and paving the way for his work on Thor and Siege.

The Adventures of Cyclops and Phoenix

The Adventures of Cyclops and Phoenix #1-4

Scott Lobdell was one of the writers tasked with the thankless role of steering the X-Men franchise after the departure of Chris Claremont. And though the '90s saw the X-books collapse under the weight of convoluted stories and editorial interference, there are some gems to be found in the period as well. Lobdell's finest work is this mini-series that chronicles the strange ties that bind the Summers family.Shortly after their marriage in X-Men #30, Cyclops and Jean Grey were whisked away to the future by Mother Askani in order to raise baby Nathan Dayspring (better known to most X-fans as Cable). The setting and tone of the story help distinguish this mini-series, and it also features one of the more memorable battles against Apocalypse, a villain who would rarely be used as well in later stories. This mini-series also features some all too rare superhero art by Gene Ha, which alone makes it worth the price of admission.

Mutant Massacre

Uncanny X-Men #210-214, X-Factor Vol. 1 #9-11, New Mutants Vol. 1 #46, Thor Vol. 1 #373-374, Power Pack #27, Daredevil Vol. 1 #238

In one of the most iconic X-Men crossovers ever, the mutants venture into the sewers below Manhattan to save the Morlocks from extermination. Unlike many superhero epics, they weren't entirely successful. Mutant Massacre is one of the more violent X-Men tales, with plenty of innocents falling victim to Sinister's Morlocks and even an X-Men being maimed in battle. Several other Marvel heroes were dragged into the battle, including Daredevil and Thor.The particular crossover doesn't hold up quite as well as some, as certain books were handled with more maturity than others. Still, Mutant Massacre is an essential read that modern X-writers often revisit and even reinterpret certain events.

Divided He Stands

X-Men Legacy #208-213

Messiah Complex ended with Professor Xavier being shot in the head and mysteriously vanishing. This paved the way for X-Men Legacy, a significant revamp of the long-running X-Men series. Mike Carey placed Xavier at the forefront of the book as the former head of the X-Men sought to rebuild his shattered memories and atone for the many questionable deeds he committed.The first arc, "Divided He Stands," was easily the highlight of this run. Carey molded Xavier into a more sympathetic and conflicted figure. The series also made excellent use of X-Men history, providing numerous flashbacks rendered by a variety of top artists. Legacy is still going strong as part of the X-Men franchise, but it was never more focused or compelling than it was in the beginning.