Famous Clocks of the world:

 
The Strasbourg Astronomical Clock
The Strasbourg astronomical clock is located in the Cathedral of the French city of Strasbourg. 
The Strasbourg astronomical clockThe current clock dates from 1843. Its main features, besides the automata, are a perpetual calendar (including a computus), an orrery (planetary dial), a display of the real position of the Sun and the Moon, and solar and lunar eclipses. The main attraction is the procession of the Apostles which occurs every day at 12:30pm, that is at noon clock time.
Big Ben in London
The Clock Tower is the world's largest four-faced, chiming turret clock. The structure is situated at the north-eastern end of the Houses of Parliament building in Westminster, London. It is almost universally called "Big Ben" — which is actually the main bell housed within the Clock Tower
 
Prague Astronomical Clock
The Prague Astronomical Clock or Prague Orloj (Czech: Pražský orloj) is a medieval astronomical clock located in Prague, the capital of the Czech Republic. The Orloj is mounted on the southern wall of Old Town City Hall in the Old Town Square and is a popular tourist attraction.
 
Rathaus-Glockenspiel (Munich)
The Rathaus-Glockenspiel of Munich is the most famous[citation needed] glockenspiel in the world, and a major tourist attraction in Munich.
Part of the second construction phase of the New Town Hall, it dates from 1908. Every day at 11 a.m. (as well as 12 p.m. and 5 p.m. in summer) it chimes and re-enacts two stories from the 16th century to the bemusement of mass crowds of tourists and locals.
St. Mark's Clock Venice
St Mark's Clock is the clock housed in the St Mark's Clocktower, on St Mark's Square in Venice, adjoining the Procuratie Vecchie.
 
Wikipedia has a more complete list of famous clocks