I'll answer the easiest first: My favourite comm badge is the "All Good Things..." version (like my avatar, just without the sea/sky background)
As for the uniform: Well, I find myself fascinated by the TOS movies "Monster Maroons" and all their permutations and intricate design elements and accessories, but they're very "military" and if I found myself as an officer in the late-23rd/early-24th century I'd go for something like Saavik's undershirt and leather vest ensemble from the end of STIII: TSFS when they land on Vulcan (where permitted). Otherwise, I like "The Cage" style velour turtlenecks as they look comfy and are not too brightly coloured. Also, the asymmetric Discovery uniforms (and their Mirror Universe versions) and the 29th century uniforms (from VOY "Relativity).
As for the uniform: Well, I find myself fascinated by the TOS movies "Monster Maroons" and all their permutations and intricate design elements and accessories, but they're very "military" and if I found myself as an officer in the late-23rd/early-24th century I'd go for something like Saavik's undershirt and leather vest ensemble from the end of STIII: TSFS when they land on Vulcan (where permitted). Otherwise, I like "The Cage" style velour turtlenecks as they look comfy and are not too brightly coloured. Also, the asymmetric Discovery uniforms (and their Mirror Universe versions) and the 29th century uniforms (from VOY "Relativity).