It depends on your criteria, really, and there's heaps to choose from. Of the ones I've seen, for pure domination, Ponting's 140-odd at Leeds should be in the conversation (or, indeed, Butcher's knock later in the same match) or either of Smith's big doubles and Flintoff's ton at TB in '05 was a ripping knock not to mention Inzi's match-turning ton in '01. For grit, Ponting again in 2005, a few of Dravid's knocks, etc. For free-wheeling entertainment, KP at the Oval and Gilchrist's 152 was just bat-**** insane mainly because you just weren't supposed to bat like that in a Test at that time. I'm sure there are a bunch more I'm not mentioning.