It's dependant upon goals. Cardio before lifting will warm the body up if the intensity is not too high, and you won't be too tired to lift. Lifting before cardio could make you tired enough to halfass your cardio at the end of your workout. Personally I've tried both, and found better fat-burning results from doing cardio first, and better strength results doing cardio last. Since I'm looking to cut, I stick with doing it first.
I think part of the problem that's making this issue so debatable is the fact that people's goals are different and a lot of people don't consider that. I've read a lot of crap discrediting cardio altogether to keep up weight room performance, and a lot of people saying that their weight-training did nothing to slow down their cardio ability, but I find that to be nonsense personally. I know when I was lifting heavier some days I didn't even want to DO cardio, let alone any intense cardio. And you always see big muscular guys in any sport gassing before better-conditioned guys. So for me getting the cardio out of the way and depleting stored glycogen is a good thing, when there's bodyfat that needs to be burned throughout the workout. I say try both, whichever works best for you...stick to it.