My Korby Audio FET condenser, which beats every microphone I've ever tried and is often compared to the Neumann U47 but costs $1200 instead of $5,000.
Second, and just as important, is the SPL Stereo Vitalizer (not the Vitalizer Jack or Tube Vitalizer). Running a whole mix through it (or individual insts / vocals) is exactly like washing a dirty window you didn't know was dirty. It is a wonderful machine. I ran a friend's CD through it (a Grammy nominee) and he looked at me and said, "Where in the world was this thing when I was recording?" Take it out of the signal path and you feel like looking for the person who just took the life out of your recording. There is no eq, exciter, or enhancer I've used that comes within a league of it.