This is getting REALLY ridiculous now! I wanted to program another ATtiny24 using my own guide and then I found ANOTHER error in the programming schematic. And this time it's a pretty big mistake, MOSI was going to the reset pin and reset to MOSI. I guess this was the reason why you couldn't program yur ATtiny24's. I can't explain how that could have happened...
Anyway, here's the corrected guide, I've also deleted the old one.
http://www.mediafire.com/file/q4232gx1w2q2w0s/GC_PSX_stick_in_N64_controller_v1.2.zipBlaze, so you got a different problem as your AVRs are already programmed. So I'm gonna tell you how you can test if the AVR is working right:
First provide power to your AVR. Leave out the cap for now but you need the 10k resistor between VCC and reset. If the reset pin isn't held high, the AVR won't run.
You can use a 3V battery or you take the 3.3V from the N64 controller, doesn't matter.
Next you provide VCC & GND to only one pot of the stick. Now you can take your multimeter and check the voltage of the middle pin of the pot. When the stick is in neutral position you should get roughly half the voltage of VCC. If you don't get any voltage at all then there's something wrong with the pcb of the stick.
Then you connect a wire from the middle pin of the pot to pin 8 of the ATtiny24. When you're moving the stick now pin 9&10 of the AVR will constantly toggle between logic 0 and 1. So now you take a simple LED and connect the short wire to GND and the long wire to either pin 9 or pin 10, it doesn't matter. But you'll also need a resistor for the LED as 3.3V is too much for a regular LED. Take a 75 or 82Ohm resistor.
Now the whole setup should look like this:

When you move the stick now you will see the LED blink. The slower you move the stick the slower the LED blinks. So if you see the LED blink, everything should be fine.
BTW, Super Mario 64 is great game to test the stick as you can see the cursor moving.