For instance, in my epic game, the party, who were all between 33rd and 42nd level, were in the Abyss, approaching Orcus' fortress. There's this COLOSSAL+ "Abyssal Dragon" (read: Ancient Wyrm Red Dragons = kindergarteners compared to this thing) who's hiding in the LAVA moat. His tactic is to wait until the party approaches, then fly into the air, splashing lava all over the PCs. That's his surprise round. Then, further tactics are to remain airborne, and pelt the PCs with 60d12 breath weapons and various spells. Truly gruesome.
So the party all have fire resistance of some sort, so the lava splash is no big deal. But the breath weapon is still strong enough to intimidate most of the party members. (Only ONE of them had complete fire IMMUNITY.)
So for the first regular round, initiative is rolled, and the mage wins initiative. In fact, all but 1 of the party members beats the dragon's initiative.
So my cousin Dusty (the party leader) and some of the other players decide to take a smoke break. Sly, the one playing the mage, is a non-smoker, so he decides to stay with me at the table. The plan is to go ahead and get his spell out of the way, so that the others can do their actions when the smoke break is over.
So, Sly's character, Sphynx, has an epic spell of his own design: Power Word, Obliterate. The HD limit is 65, and the dragon is only (only...

) 60 HD, so he can possibly be affected. The spell had a long range, and the dragon was still well inside it.
Sphynx manages to break the dragon's SR of 50 (pretty easy for a 42 Wizard) but the dragon's saves are SO GOOD, that he beats the DC 48 on a 2 or better on the d20....
...wait for it...
I rolled a 1.

There it was, the epic battle I had been planning for two weeks, gone with a single spell. I was dumbfounded. It was Smaug all over again. One lucky shot. BAM!
The other guys came back from their smoke break to find the dragon dead. They were SO non-plussed. All of them had been discussing their plans of attacks, and were looking forward to trying out new feats, new magic items recently acquired, etc. Of course, after a few minutes, they started congratulating Sly on his slick use of an epic spell. And a great night of roleplaying still ensued.
But when I look back on it now, I laugh and laugh and laugh. Of course, they still had their hands full with Orcus himself. And the module was GREAT FUN. But I think the thing I loved MOST about that adventure was the sudden dragon death. It's like
Indiana Jones when he just shoots the swordsman after watching his little display of prowess.
And it's a reminder that even the toughest foes can be defeated, and sometimes, when you least expect it, and by someone you might be tempted to underestimate.

Cheers!
