2 that spring to mind straight away:
Turkey v Czech Republic from Euro 2008 - Turkey came back from 2-0 down and scored 2 in the last minute I think. 1 from a bad error by Cech and then a belting finish from Nihat to win the game.
Argentina v Peru in the world cup qualifiers last year. The game itself wasn't that great, but the ending was just epic. A biblical rainstorm, a shocking equaliser for Peru, a last gasp winner from Palermo, and even then Peru took a shot from the ensuing kick off which hit the bar. Not to mention Maradona sliding across the pitch on his belly! Well worth staying up late to watch that one.