Any metal species which has more than one type of ligand is heteroleptic.
For instance dialkyl magnesium complexes, which are found in the equilibrium which exists in a solution of a Grignard reagent in an ether, have two ether ligands attached to each magnesium centre.
Another example is a solution of trimethyl aluminium in an ether solvent (such as THF); similar chemistry should be expected for a triaryl or trialkyl borane.
It would still be reasonable to consider a complex which has only one type of ligand but with different coordination modes to be homoleptic.
For example, the complex dichlorotetrakis(dimethyl sulfoxide)ruthenium(II) features DMSO coordinating via both sulfur and oxygen atoms (though this is not homoleptic since there are also chloride ligands).