For a great many fans of both Quentin Tarantino and James Bond, this is the one film that might have been which stings most of all.
From the late 1990s onwards, it had been strongly rumoured that the director wanted to shoot a period-faithful adaptation of Ian Fleming's original James Bond novel, which had not been made as a canonical entry in the Bond series at that point (the 1967 spoof is an entirely distinct from the official movie franchise).
The plan was to make it with current Bond actor Pierce Brosnan, who is believed to have been excited about the idea; Uma Thurman was mentioned as a likely choice for Vesper Lynd. However, it seems the idea didn't go down so well with Bond producers Barbara Broccoli and Michael G Wilson - and after they turned him down, Tarantino entered a bidding war against them for the rights to Fleming's first novel, hoping to make it as a standalone film of his own.
Of course, the rest is history: Eon secured the rights, retired Brosnan, hired Daniel Craig, brought back Goldeneye director Martin Campbell (who, again, would go on to Green Lantern), and made their own Casino Royale in 2006.
Given it's one of the best Bond movies ever, we can't really complain; but Tarantino has argued the film wouldn't have been made at all had he not tried to make it first, and it's hard not to agree with him.