So you got House of M
then following House of M there'sX-Men: Deadly Genesis
. This follows up on a couple of loose plot threads from House of M, and is one those "dark secret from the X-Men's past rears its head" type stories.
Featured X-Men in this story include Cyclops, Marvel Girl (Rachael Summers), Wolverine, Prof. Xavier, and Banshee. Non-essential, but it does cover a couple of salient storylines from House of M. It's decent enough.Uncanny X-Men: Rise and Fall of the Shi'ar Empire
is the direct sequel to Deadly Genesis. It's an X-Men/Starjammers in space story. Non-essential, but if you like X-Men in space... (and I do). Featured cast: Xavier, Havok, Marvel Girl, Polaris, Nightcrawler, Warpath, Lilandra, Corsair, Hepzibah.
Around the same time, X-Men: Supernovas
features a new, more pro-active team of X-Men back on earth. This is where the build towards Messiah Complex starts, but again it's not absolutley essential. Featured cast: Rogue, Cannonball, Cable, Mystique, Sabretooth, Iceman, Lady Mastermind, Omega Sentinel.X-Factor
is sort of a side book about a mutant detective agency, but it deals heavily with the "street level" impact of House of M and also features one of the major characters from that event. If you like X-Men with a noir feel, you will probably like this. Cast features: Madrox (Multiple Man), Strong Guy, Siryn, M, Rictor, Wolfsbane, and Layla Miller.
(There was also a prequel mini-series
about Madrox that took place before House of M.) These are non-essential, although Madrox and Layla in particular play large roles in Messiah Complex. (There are 4 volumes total of X-Factor that come before Messiah Complex, although the trades for this series are smaller)Uncanny X-Men: The Extremists
covers the return of (some) of the team from the Shi'ar storyline's return to earth, to put them back in play. Non-essential.X-Men: Blinded by the Light
is the continuation of the Supernovas cast and leads directly into the Messiah Complex crossover. Essential if you read and enjoyed Supernovas.Messiah Complex
was a big event story that crossed over the 4 main X-titles at the time (Uncanny, X-Men, X-Factor, New X-Men). Essential reading, this sets up the direction for the entire X-universe for the forseeable future.