1. Jeans (long), snug but not TOO snug, boots of any sort, and NO shirt.
2. most any military uniform, esp Navy. (I tried one on once and the sexual jolt -- and power -- I felt was amazing.)
Also cop uniforms -- assuming the guy is beefy and masculine. On any other guy, these would look ridiculous.
3. cowboy hats, boots, denim..that whole look, with or without shirt.