Citizen Eco Drive. Very elegant, no battery replacements, durable, lasts for weeks with no sunlight (it's a solar-recharging watch...). IMO the ultimate watch for a general elegant look at work that can be used any day, and they come in many styles from more rugged and water resistant divers to chronographs and also more elegant classic minimalist designs...

Or if you only need functionality and are OK with a more retro look (or are an engineer), the classic Casio F-91w is impossible to beat! Also the W-59 with slightly more water resistance rating or the f-105w-1a (illuminator model, just a much nicer backlight...).