Musitek SmartScore Midi Edition
Though it's limited to four staves, SmartScore MIDI Edition is enough for most users looking to turn their sheet music into MIDI and notations files. The interface goes a bit overboard with the floating tool palettes, but the program does a very good job transcribing simpler sheet music. At $49, it's a lot more affordable than the $400 Pro version, though you'll need that pricier option if you're looking to recognize full orchestral scores, or lyrics and text. There is a full version comparison on vendor Musitek's Web site.
--Jon L. Jacobi