Police uniforms and military fatigues and military formal attire. I'm prejudiced, I reckon, as my husband was in the service for many years and then an officer - and he still turns me on after all these years! I'm with duffsmom here, there is something innately masculine about them, especially if the man is actually serving the position of the uniform.
Actually it's never about the uniform bur rather the person wearing it. Having said that I've always been partial to the "French maid" uniform which more often than not is worn as a costume these days. lol! Seriously speaking if someone is "hot looking" I doubt it matters what type of uniform they are wearing as long as it is clean.