Our single-breasted navy suit is a best-seller for a reason. It goes with everything, it's versatile enough to wear as a casual jacket, and it's easily punched up with wedding-worthy accessories, from pocket squares to lapel pins. Don't be afraid to experiment with different shades of blue, either. Petrol and slate can both look smart, depending on the season. Just remember to match your belt and shoes—brown with brown, black with black.