Well, weight training IS exercise. The answer really has to do with what you're capable of doing and how your body responds to stimulus. I will say that I probably "looked my best" when I was both training for a half marathon and doing heavy weightlifting. Of course, I was also in my 20s
It also depends on how you want to shape your body. It's common for men to want "V-shaped" upper bodies, while some women would hate that look (although some women would also be very happy with it!). Weightlifting can help "exaggerate" your features, if you wanted to bring attention to particular ones, while more aerobic-based exercises can "carve" into fat.