I love lenses with character.   I prefer to use vintage lenses as they come with some character, whether that be weird bokeh, lens flares, distortion or close-focusing wide lenses - a lot of this stuff you don't get on modern electronic lenses in exchange for AF and IS.    I love lenses that flare like crazy such as the Helios 44-2, yellow coated Super Takumars (like the 55mm) and the strange Mir 1B 37mm - all very creamy, odd and unique looking.    I absolutely love wide lenses that have