I would suggest doing both. I believe interval training is the best because you can target both the aerobic and anaerobic systems at the same time. This will force your body to burn more calories and get you in better shape faster. Of course, don’t forget diet plays a major part in your fight to lose weight. If your diet is not almost perfect and ‘clean’, then it doesn’t matter much what you do for a workout. Unless you are a super athlete or a pro (like an ultraendurance athlete, marathoners or a competitive swimmer) then the amount and quality of calories consumed would affect your ability to lose weight, no matter the type of training you choose. And I would be more concerned with your overall fitness level than how you look because in the long run, that’s more important than moving up or down a few pounds. If your only concern is looking better, you cannot “spot lose” to perfect problem areas, so your best bet is to do everything you can to be as fit as possible. Those areas will improve, as will your overall health.
Body fat % is more important than pounds on the scale.
As has been so well addressed, both are critical aspects of any fitness training program, weight loss included. Don’t forget flexibility exercises. Although not necessarily targeted to weight loss, flexibility is a crucial component of overall fitness. And, of course, sensible nutrition.