http://www.cracked.com/article_18904_6-heroic-movie-deaths-that-could-have-been-easily-avoided_p2.htmlGandalf kind of cheats the "dramatic death" thing by coming back in the second film of the series, but he clearly didn't know that when he chose to stay behind to fight the Balrog so the rest of the Fellowship could get away (though the Fellowship just stands there and watches the fight instead of actually getting away).
Actually, the Fellowship seems to have a good 30-second head start on the Balrog, as everyone else is up the stairs and almost out the door before they even notice Gandalf hanging out in the middle of the bridge waiting for the flaming death beast to arrive.
Gandalf's plan seems to consist entirely of "break bridge so YOU SHALL NOT PASS." He starts talking smack to the Balrog about what a badass wizard he is, again probably to give the not-running-away Fellowship time to leave, and when that doesn't make the monster back down, he cracks the bridge as the Balrog is crossing, causing it to fall into the dark chasm below, directly in front of him. The Balrog is so close, in fact, that it's able to grab him as it goes down, and bam, no more wizard protection for the Fellowship.
Wait a second ...
There was no reason Gandalf had to wait that long to break the bridge, or break it from the center like he did.
If he had crossed all the way, broken the bridge and then kept running before the Balrog caught up to them, they all would have been in the clear, and they wouldn't have lost their wizard for the better part of two movies. Or even if he did exactly what he did but then ran away, he would have been fine. Instead, he waited in the very center for as long as humanly possible before cracking that sucker, and then he just hung around as it fell, even though goblins were still shooting arrows at them from across the chasm.
Then again, maybe we can blame the Fellowship for this one. If they had run away like they were supposed to, maybe Gandalf wouldn't have felt the need to drag out this bridge-destroying thing for as long as possible and gotten himself temporarily killed.