I just know that, if it were me playing "Jeopardy!" and the category of "Game Shows" came up, the MILLISECOND I had control, I'd start picking clues in it. Why? The intimidation factor.
Everybody that gets on "Jeopardy!" is smart; hell, most of them are smarter than me! So, having the brains to get the questions is a given; the rest of the game deals with luck, momentum, and intimidation. You obviously can't control luck, so why not go for the two things that you CAN?
Personally, I'd love to see the looks on my opponents' faces after running a category; time and time again, I've noticed flustered opponents after somebody runs a category on the show and it usually takes a good 2-3 clues to get back on track; run it early, and you could be the one setting the pace for the rest of the game. Plus, with the amount of confidence one would gain by getting 5 in a row, suddenly that "Advanced Quantum Physics" category doesn't seem so hard anymore, right?
So, in short: Who cares about the "Daily Double?" Just get the money that you know you can get and the rest will fall into place (in fact, getting a "Daily Double" would probably scare me to death because I'd have to answer the question and be forced to either gain or lose money; at least, with the rest of the clues, I can simply lay my thumb to rest!).
Anthony