Considering Superman or Green Lantern could probably beat down the X-Men on their lonesome... yeah... Justice Leauge vs Avengers is more equal but been there, done that.
Actually, Avengers vs JLA is a gay match-up, JLA would wipe the floor with the puny ass monkeys of the Avengers. On the other hand, Xmen and JLA would be a kick @$$ match-up. I think it'll be a tie.
I say X-men, with Xavior and Jean Grey's telepathic abilities they could take control of the JLA's most powerful members. Also Batman knows all the other JLA's weaknesses, which means Xavior or Jean Grey or Rouge could take that info from him and use it against the JLA. Additionally the X-men have enough strong Brawler type fighters to defend Xavior and Jean while they do their telepathic attacks. Iceman alone could incapacitate quite a few of the JLA by instantly freezing their blood in their bodies.
Rogue could take info, and how do you propose she does that? Superman alone could just use his heat vision to burn away her hands, leaving her incapable of taking anyones powers.
Xavier would get shut down by the flash. Who effectively can hit someone like a couple thousand times in a second, if not more. Iceman has no chance of catching him, nor does Quicksilver.
It's an interesting fight, actually. I hadn't thought of a couple of X-Men characters that could be central to them winning. But still, poor comparisson, Justice League would annihilate.
Iceman doesn't have to catch anyone he can mentally freeze the blood flow in a persons body pertty much instantly. Jean could produce a force feild around herself and Xavior to protect against the Flash, and Superman just isn't as strong as he use to be, if you read his new comics as opposed to those in the 50s 60s 70s ect...
There are dozens of them if you count all of the minor characters that have lived at the institute over the years. Or do you mean the original team or the main characters. Would you include Jean even though she is dead? Probibly about 100 super powered x-men characters against the JLA would be a walkover for the x-men.
Would you include Magneto or other rivals of the x-men?
I'm not saying the shield would stand up forever just saying it'd be an obstacle. Also the other X-men would be fighing with the JLA, so it's not like they'd be able to exert all their resources against Xavior and Jean. From what I understand of the Flash he's fast but not any stronger than a normal human (or not by much) I mean he can't phsically lift cars and stuff? There are ways to defeat every character and Flash is no exception saying he would take down Xavior and others, and there is nothing they can do about it cause he's fast doesn't make sense. Fast opponets have been defeated before many times.
While the JLA are atacking the shield do you think Xavior would do nothing? Or the others? If we're going by the major characters who are on the team for a significant period of time they've got the JLA out numbered. While I know it doesn't mean they'll win it certainly helps.
Techincly if it comes to a full roster fight X-Men would win since the amount of mutants who have lived in the mansion seem to number in their early thousands. And besides I think we've forgoten one important thing Xavier's mind is the house of Onslaught since Onslaught was Xaviers hate for humanity fused with Magneto's and since in a full roster fight Mags would be there Xavier could recreate the psycho psychic force to kill thr JLA. And he would because both Mags and Xavier are willing to go to any length to protect what they think is important. The sad thing is Onslaught can't be controlled and would most likely kill everyone.
Oh and a question shouldn't the Flash's speed make him hit harder, I'm fairly sure I heard a formula that states the faster you go the more force you have. If this is true then the Flash could do a lot of damage with one punch.