There's little harm in listing previous jobs. I might skip the job at Wendy's in high school, but I'd definitely list any full-time work experience unless it's something you really don't want to disclose. If you're a nontrad, a program might like an idea of what you were doing before medical school.
One piece of advice I received is that the work experience should answer a couple questions. First, does it explain a gap? Then put it in. Second, is it health/science related and can thus inform your experience? Then put it in. I guess I would add that if you need the whole list for both those questions then do it. It'll make your CV longer, but it'll give you things to talk about right?