Whatever else may be said about Quake II, one thing is certain: It is the only first-person shooter to render the original Quake entirely obsolete. Within moments of starting the game, it is safe to say that all but the most irrationally loyal players will acknowledge that Quake II is better than the original in every respect, and that no one who can afford to upgrade will have any reason to ever load Quake again. Considering the countless hours invested by countless players in the game, that's a remarkable achievement. It's also significant because since Quake shipped 18 months ago, we have seen a steady stream of challengers, games that have been trumpeted by press and players alike as the successors to the first-person throne. But none of these games has actually come through on that count - not Hexen II, not Jedi Knight, and certainly not any of the half-dozen "Quake Killers" that have yet to make it out of alphaland and onto store shelves. But Quake II does come through, delivering at le