Here are some games I've tested.
I used the following settings for each game:
Texture Update Check - Disabled
Frameskip - 2
Limit Framerate - Yes
Dymanic Recompilation - Enabled
Audio - Disabled
OK, now the games:
Diddy Kong Racing - Menu text appears but all other graphics do not.
Verdict: Unplayable
Banjo-Kazooie - A few minor texture errors, runs rather slowly.
Verdict: Playable, but slow
F-Zero X - Doesn't Load at all.
Verdict: Extra Unplayable =O
Kirby 64 - Loads, there's sound but no picture. You must load it without sound then turn sound on when it has loaded.
Verdict: Unplayable
Mario Tennis - Major graphical errors, freezes when a match is started, slow, corrupt memory message appears at title screen.
Verdict: Unplayable
Mischief Makers - Minor graphical errors, runs at full speed even with sound on, freezes when a file is created but when the game is reset, the file can be loaded. Character speech text does not appear, crashes when the creatures invade the old man's house.
Verdict: Unplayable
Paper Mario - Loads, opening story runs at full speed with audio, major graphical errors on file select screen and opening story, crashes when a new file is created.
Verdict: Unplayable
Ridge Racer 64 - Major graphical errors, run at full speed with the settings mentioned above, corrupt save data message at title screen.
Verdict: Playable
South Park - Doesn't load
Verdict: Extra Unplayable =O