Here's a list of files that simply don't load:
Famicom\Namco\Sangokushi_2.nsf -- Loads, locks Winamp up.
Famicom\Nintendo\Link_no_Bouken.nsf -- Loads first song, all others lock Winamp up.
Famicom\Nintendo\Pro_Wrestling.nsg -- Won't even load.
Famicom\Sigma\Musashi_no_Bouken.nsf -- Won't even load.
...and a list of files that exhibit odd audio (although, it's just possible your audio emulation is _more_ accurate than Nezamp):
North America\Ascii\Gun_Nac.nsf -- Exhibits popping, probably noise channel
Famicom\Data_East\Kiken_na_Futari.nsf -- Exhibits popping, probably noise channel
Famicom\Seta\Silva_Saga.nsf -- Exhibits popping; may be intentional
Famicom\Nintendo\Shin_Onigashima.nsf -- Exhibits popping on square/triangle fade-in (really odd, check this one out)
Famicom\Taito\Chase_HQ.nsf -- Exhibits popping; noise channel, obviously
If you need any of these, let me know. Send email to firstname.lastname@example.org.NOSPAMTHANKS and I'll let you find me on AIM/ICQ/Yahoo/MSN. Woop.