I'm sure you'll get lots of advice on the subject, but I can only speak for my own personal experience. Last year I was in the same situation as you - I'm 6"5 and was 3 stone overweight. Never huge, but carrying enough additional weight to feel uncomfortable. My diet wasn't brilliant (although it wasn't terrible either), and I suffered from acid reflux, and was on meds from the doc for it. Add in a stressful job, lousy sleep most nights, and I wasn't in the best shape.
Purely on chance, I read a posting about weight loss on another forum (bass guitar one, strangely enough), and someone recommended the South Beach Diet. I did the usual "I'm a bloke, I don't diet" thing, but ordered the book from Amazon anyway. Best thing I ever did. The book was written by a heart consultant, so it's more science-based than mumbo-jumbo, and it's pretty much common sense. You basically cut the crap out of your diet, eat 3 healthy meals a day, plus snacks, and watch the weight drop off! I lost 3 stone in a year, my reflex disappeared (so I don't need meds any more), sleep better, and generally feel much better. It's in 3 phases: first one is strict, where it weans you off sugar / carb addictions, but it only lasts 2 weeks. Second phase re-introduces bread etc (in moderation), and you stay on this until you reach your target weight. Third phase is just maintenance, and is really just good healthy eating. There's no "you can never have a beer or curry again" mentality, nor is it a no-carbs diet (just the right carbs) so it works well for me.
Oh, and alongside this, I did a Couch to 5k running program, too. Better diet + moderate exercise = weight loss and feeling better. Who'd have thunk it?