It's a game I didn't even know existed until earlier today, and although this 1988 battle between two legends and former world champions was only a blitz game, it's still absolutely worth watching.
Boris Spassky, in a must-win situation with the black pieces, essayed the Pirc Defense. It's not a bad choice in general, though it is rather provocative against a player like Mikhail Tal. (In fact, I know of one reasonably decent player* who had been successful with the related Modern Defense, managing to beat even titled players in tournament games with it. He thought it would be a smart idea to use against Tal in a simul...and got obliterated.) Tal used the Austrian Attack, arguably the most principled reply, and they followed an earlier game of Spassky's until the latter varied with a logical and ambitious new move.
Logical, but mistaken. With some fine prophylactic moves Tal prevented Spassky from implementing his plan, and then Tal turned his attention to what he did best: attacking the enemy king. While he did miss some little improvements along the way, it was an impressive performance - especially for a blitz game - and it's an instructive game for anyone who plays that line with either side.
So have a look here for all the details. The show is free, as always (free registration required), and will be available on-demand for the next month or so.
* That would be me.