I took all of the microphones I could find and recorded them with my Nikon D3200. I somehow misplaced the actual mic capsule for my GE desktop mic base and I don't have access to the RadioShack lav mic at the moment.
I played the "March" and "Jig" parts of The Old Bachelor by Henry Purcell (1691). Sub was turned up pretty high to test the bass response of each of the mics. Gain was manually set for all of them to within -3 to -12Db from clipping (mainly 11/20 on the Nikon)
To start:
Onboard camera mic (mono)
Opteka VM-100
I picked this one up from a vendor at the NW largest "garage" sale for $10. It's supposed to be a clone of the original Rode VideoMic. Mono.
Realistic 33-1065 Stereo mics
Lots of preamp hiss, had to turn the gain up to 17/20 even though I had a charged battery in it. Midrange-heavy.
Zeniko OC-D1 stereo mic w/swiveling capsules
Surprisingly not as good as I thought they were. Has a slight peak in the mids.
Tascam TM-2X
This one really surprised me, even though it's only rated to ~50Hz -3Db. Fuller and richer than any of the other mics. Sounds much closer to what I heard with my ears. Might have to use this from now on.