There are many examples of every possible d electron configuration. What follows is a short description of common geometries and characteristics of each possible d electron count and representative examples.
:d
:Commonly tetrahedral; however it is possible for d complexes to accommodate many electron pairs (bonds/coordination number) since their d orbitals are empty and well away from the 18-electron ceiling. Often colorless due to the lack of d to d transitions.  
:Examples: titanium tetrachloride, titanocene dichloride, Schwartz's reagent.
:d 
:Examples: molybdenum(V) chloride, vanadyl acetylacetonate, vanadocene dichloride, vanadium tetrachloride.
:d
:Examples: titanocene dicarbonyl.
:d
:Examples: Reinecke's salt.
:d
:Octahedral high-spin: 4 unpaired electrons, paramagnetic, substitutionally labile.
:Octahedral low-spin: 2 unpaired electrons, paramagnetic, substitutionally inert.
:d
:Octahedral high-spin: 5 unpaired electrons, paramagnetic, substitutionally labile.
:Octahedral low-spin: 1 unpaired electron, paramagnetic, substitutionally inert.
:Examples: potassium ferrioxalate, vanadium carbonyl.
:d
:Commonly octahedral complexes in both high spin and low spin. 
:Octahedral high-spin: 4 unpaired electrons, paramagnetic, substitutionally labile.
:Octahedral low-spin: no unpaired electrons, diamagnetic, substitutionally inert.
:Examples: hexamminecobalt(III) chloride, sodium cobaltinitrite, molybdenum hexacarbonyl, ferrocene, ferroin, chromium carbonyl.
:d
:Octahedral high spin: 3 unpaired electrons, paramagnetic, substitutionally labile.
:Octahedral low spin: 1 unpaired electron, paramagnetic, substitutionally labile.
:Examples: cobaltocene.
:d
:Complexes which are d high-spin are usually octahedral (or tetrahedral) while low-spin d complexes are generally 16-electron square planar complexes. For first row transition metal complexes such as Ni and Cu also form five-coordinate 18-electron species which vary from square pyramidal to trigonal bipyramidal.
:Octahedral high spin: 2 unpaired electrons, paramagnetic, substitutionally labile.
:Square planar low spin: no unpaired electrons, diamagnetic, substitutionally inert.
:Examples: cisplatin, nickelocene, dichlorobis(ethylenediamine)nickel(II), iron pentacarbonyl, Zeises salt, Vaskas complex, Wilkinson's catalyst.
:d
:Stable complexes with this electron count are more common for first row (period four) transition metals center than they are for complexes based around second or third row transition metals centers. These include both four-coordinate 17-electron species and five-coordinate 19-electron species.  
:Examples: Schweizer's reagent.
:d
:Often tetrahedral complexes limited to form 4 additional bonds (8 additional electrons) by the 18-electron ceiling. Often colorless due to the lack of d to d transitions.  
:Examples: tetrakis(triphenylphosphine)palladium(0), nickel carbonyl.