Virtually all ligands are known to bridge, with the exception of amines and ammonia.  Common bridging ligands include most of the common anions.
Many simple organic ligands form strong bridges between metal centers.  Many common examples include organic derivatives of the above inorganic ligands (R = alkyl, aryl): , , ,  (imido),  (phosphido, note the ambiguity with the preceding entry),  (phosphinidino), and many more.