Shimano PD-R540s for me on both my road and track bikes. I do lots of standing start stuff on the track bike and I have so far not had a problem in 2 years of use and abuse. The road pedals are just as old, cop less abuse in terms of the starts, but are exposed to the elements much more. I was tipping the scales at 140kg and am now hovering around 120kg.
Take a look at the spec sheets for the different Shimano pedals if you're interested. The only real gain you get when going from the 540s to the 105s and Ultegras is different materials used. The critical internals like the bearings only change when you go up to the DuraAce pedals.