Have beaten Spyro 1 and 3 and recently started YotD. No bugs yet.

You mean 1 and 2?

Wow, that's really weird! O_o Seems Sgt. Byrd was barely tested at all.

Poor boy.

He's still fun for me to play, though, which I'm fine with.

+1 to the camera control in Sgt Byrd's levels.
Flying through the Lava Tunnel is practically impossible to see where you are going.

Speaking of Sgt. Byrd, I was playing through the level with him were you fight the cat witches. On the final stage where the ground is turned into a blue liquid, the camera glitched out, and everything turned blue. The music also turned into a really loud drone. The glitch ended when I beat all the witches, though, which was possible (despite not being able to see!) in RT with Byrd's tracking missiles and such.

I loved the skateboarding in the original, but the physics are so wonky that it's pretty much unplayable. For example, Spyro will sometimes bounce off of walls instead of just crashing, and sometimes he gets stuck on the walls. Then there was the yeti race... when one of them would come up behind me, the snowboard would disappear and Spyro would be running for a second before it would reset me onto a new board.

The camera in Sgt Byrd's levels is terrible and sometimes flips completely upside down. This seems to be triggered by hitting the ceiling.

I know there were more, but I can't think of them at the moment. Spyro 3 was definitely way less polished than the other two.

I've been lucky enough that I've gotten through most of Spyro 1 and 2 without any bugs yet, but I've heard of some bad ones.