I think the type of underwear is as important or even more important than the cut of jeans or pants in showing a bulge. Of all the jeans and pants I've ever owned, I can only recall one that I would say was truly "accentuating."
On the other hand, in my experience any boxer brief that has a pouch in front, or that is 5-10 percent lycra or spandex, is likely to hold everything up front and center, creating the strongest possible "basket" effect.
By the way, I second voyeuristic's opinion on pleated pants. Granted, they're roomier up front, but they are SO far out of style that any bulging you may gain will be obscured by the fog of stodginess surrounding you.
Steve