Most people would say yes, including me, but I just spent an interesting time with someone who built a bench with a 2 degree slope on it. On purpose. And it felt so weird.
His argument was that any liquid spill would quickly work its way towards the front of the bench then on to the floor, he viewed this as a better alternative than the liquid sitting there in a puddle and possibly damaging equipment. Thinking about this I can also see a need for a bench that slopes towards the back, which means no more tiny screws rolling off of the bench onto the carpet never to be seen again.
Thoughts?