Cartier Ballon Bleu de Cartier

Cartier's modern round watch, and one of its biggest sellers of the last two decades. The Ballon Bleu is instantly recognizable for one detail: a rounded, almost pebble-like case with the crown tucked inside a protective guard, capped by that signature blue sapphire cabochon the name refers to. The dial keeps the Cartier grammar, Roman numerals, railway track, sword hands, floating under a domed crystal. It comes across a wide size range, with the larger 40 and 42mm models automatic and the smaller sizes quartz, in steel, two-tone, and gold. (Its dressier jewelry cousin, the Ballon Blanc, has been discontinued.) It's a softer, more contemporary alternative to the angular Tank and Santos, and an easy everyday Cartier.