Constellation

At 28mm this is the smallest case in the Constellation range I've catalogued here, and the specs shift accordingly: quartz movement instead of automatic, and 30m water resistance instead of 50 or 100. None of that is a flaw — it's Omega building an appropriately scaled, lower-maintenance watch rather than cramming an oversized automatic movement into a small case, a mistake plenty of brands make. The blue dial and steel bracelet keep it versatile rather than overtly formal. Without a manufacture designation on the movement or a complication beyond timekeeping, the case size and dial finish are doing most of the work here, and at 28mm they do it well.