The most popular styles of men's brown leather boots include Chelsea boots, dress boots, chukka boots, and lace-up work boots. Each style offers its own unique blend of formality and function, allowing you to choose a boot that fits your personal style and intended use. Chelsea boots are known for their sleek, pull-on design, while dress boots offer a refined look for more formal occasions. Chukka boots and lace-up work boots provide a more casual or rugged appearance, making them ideal for everyday wear.