Metal Compounds that bond covalently
There is no sharp line between ionic, metallic or covalent bonds. 

Most of transition metal oxides and sulfates have strong covalent characteristics. For example, the whole reason of using ligand field theory instead of crystal field theory is that the ionic description (CFT) breaks down, and the covalent effects are important in all but the simplest cases. 

If you want to take even more covalent molecules, look for organometallic compounds, metal carbonyls, metallocenes, etc.