Rolex Paul Newman Daytona Ref. 6263
Daytonas with exotic dials were unofficially named for the late actor after he wore one on the cover of an Italian magazine. "There are rarer versions, but the 6263 with the 'Panda' dial is one of my favorites," says Charles Tearle, Sotheby's Head of Watches, Asia.
Value: $80,000

Patek Philippe Ref. 1518 In Steel
"The 1518 was made in steel only during an embargo on gold in 1940, and even then only for the Italian market," explains Tearle. "It was also the first perpetual calendar chronograph wristwatch ever available to the public." Only four exist.
Value: $1,000,000

1960s Jaeger Lecoultre Polaris
According to Tearle: "Fewer than 1,500 examples were ever made, and few have survived, likely because the Polaris is an underwater alarm watch." It has 16 holes in the back cover that allow the dining alarm chime to ring loudly.
Value: $15,000

1950s Breguet Type XX
"The Type XX was originally made for the French military and was later made available to the consumer market at the same time. It's just a great-looking, masculine-but-simple chronograph from a great manufacturer."
Value: $12,000 or so (depending on variations)

Omega Speedmaster Ref. 2298
It's not rare, but it is historical. "In 1969 the Speedmaster was the first watch to reach the moon, but the 2298 went to space seven years earlier when astronaut Walter Schirra wore his own during the Sigma 7 flight."
Value: $10,000