which workouts are best

I work in a call centre and I'm pretty much sitting for the better part of the day. I do stand and stretch and go on little walks but as I'm nearing 40, as a woman and mum that comes with a spare tyre around the middle which I'm losing the battle on. I've spent a few years getting better with food intake and I'm now exercising regularly - daily. Which workouts would be best in helping me to lose weight and get to a healthier weight for me. My BMI is approx 24 or 25 and i weigh about 64kgs (sorry i don't know what that is in pounds).