As others have said the Makopad/Superpad are ok. I've had issues with the rumble/memory card slot on some of these controllers though. When you have a memory card or rumble pak inserted they sometimes don't work. It's happened on a couple that I've had. Otherwise they work just fine.
The Hori pads are excellent. Joystick is a tad sensitive for my liking.
There are also the Ascii Pad 64 and also the Hudson Joycard which are really good controllers. The Ascii pad has an OEM Nintendo joystick.
Outside of these controllers there really aren't anything worth trying.
I'd like to point you to this website which has absolutely wonderful reviews of tons of N64 controllers
http://s9.zetaboards.com/Nintendo_64_Forever/topic/7186633/1/#new