If I were to reboot X-men, I would have to start with a Xavier meets Magneto storyline.
Movie 1 - The Brotherhood
The movie would be completelty based on Uncanny X-men 161, and 321 without the Legion quest/Brood Invasion stuff, and be set just after the Vietnam War.
Cast
Tom Hardy as Prof. Xaiver
Cillian Murphy as Erik Lehnsherr
Selma Blair as Gabbrielle Haller
Ciaran Hinds as Baron Wolfgang von Strucker
Movie 2 - X-men
Would be a mash of two storylines. Basically X-tinction Agenda, and Uncanny X-men 1 with some of my own changes. A rogue military sect called the Magistrates are killing Mutants left and right and holding the entire island of Genosha hostage with Nuclear Warheads. Erik and Xaiver have a disagreement on whether they should help. Erik leaves to Form the Brotherhood of Mutants. Xavier starts to train students to defend themslefs and others. Magneto and his B.O.M. kick the Magistrates a$$, they find out they used to be US military and hold the US responsible and now threatens to send the Warheads state side. X-Men runs interferance and beat the B.O.M. and the US forces arrive(S.H.E.I.L.D.) arrest Mags, with a cameo appearance of Nick Fury. Also a final scene that sets up a sequel which Bolivar Trask asking th President for permission to start the Sentinel Program.
Cast
Scott Glenn as Prof X
Jared Padalecki as Scott Summers
Sophia Bush as Jean Grey
Chad Micheal Murray as Warren Worthington
Luke Barnett as Bobby Drake
Jeff Daniels (VO) as Hank McCoy
(I would get the Jim Henson company to do a Beast puppet, and Beast would be CG in the action scenes)
Danial Day Lewis as Magneto
Vincent Cassel as Bennet du Parris
Lizzy Caplan as Wanda Maximoff
Robert Kazinsky as Pietro Maximoff
Jaime King as Regan Wyngarde
Cyril Raffaelli as Mortimer Toynbee
David Anders as Cameron Hodge
Samuel L Jackson as Nick Fury
William H. Macy as Bolivar Trask
http://www.imdb.com/
just use the search function.