After deciding to paint over the stock oak finish of one of our bathroom vanities, I removed the door and drawers and hardware. The high gloss paint I first applied produced an odd effect - the grain of the original finish seemed to show through, producing an uneven appearance So after a couple of coats (and one of primer), I covered it all with semi-gloss black. The end result is much preferable.
(This picture is actually of the high gloss, but it gives the effect. The mirror above the vanity is also painted.)