Sinister cause he knows more (I think) about mutants (history, origin) than most anyone else which would give a good story line though maby better for X4 so Scott and Jean can get togather again.
Gambit, cause he rocks
Cable and or Bishop, to give "look at what will happen if" story plot
More villians to bolster Brotherhood ranks
Which mutant do you think should they add to the movie X-Men 3?
Gambit
Archangel
Beast
Magma
Psyloke
Banshee
Quicksilver
Scarlet Witch
Blob
Avalanche
Destiny
Havok
Mesmero
Marrow
Multiple Man
Cannonball
Wolfsbane
White Queen
Sunspot
Berzerker
Magik
Dani Moonstar
The Morlocks
Forge
Dazzler
Longshot
Sinister
Goblyn Queen
Omega Red
Cable
Boom Boom
Bishop
Phalanx
Artie
Leech
Maggot
Onslaught
i don't know how much more of the x-men material that singer and his crew need to cover, but i'd like to see 2 more sequels before it fades out of popularity/interest.
mutants for x3: havok, psylocke, dazzler, scarlet witch, quicksilver, gambit, avalanche, berserker, wolfsbane, magma, boom boom, sunspot, beast, angel
It would be cool to see both Scarlet Witch and Quicksilver cause they are Magneto's kids. Also Beast, and have Angel and Gambit, not as students at the school but as friends of Xavier (Beast and Angel were two of the origonals). Oh and Jean Grey has to come back or it would be a bummer. And wasnt that Jubilee on the first one when Rogue meets Iceman.