The most popular or well known choices frequently are not what the true aficionado would select. Watches, like anything, are quite a personal thing. Audemars Piguet (owned and loved), Blancpain, Chopard, Franck Mueller, IWC, Jaeger-Le Coultre, Patek Phillipe are all high quality names. Pieces in your brother's price range should include Breitling, Cartier, Ebel, Omega and Rolex.
I've owned a Tag-Heuer for years and still love it. Purchased about 14 years ago, the one time I've had an issue with it, T-H repaired and returned for a very minimal fee. I would not hesitate to buy another.