How much time do you have at the zoo?
Probably 3 hours? I don't know how big the place is or if that is enough time?
The 2 best newer displays are the polar bear, and the penguin, which are up towards the entrance. I'd start with Polar Bear, then go straight to penguins. Then, after that, decide if you want to do the Africa loop or not. The Africa section has some good displays (Hippo, Baboon, Chimp, Gorilla, Crocodile, Lion) and some kinda lame ones. With 3 hours you could do Polar Bear, Penguin, and Africa, or stay up towards the front of the zoo and see the Asia/Australia display. Tigers and Orangutans are cool, and the kangaroos are a decent display. You could also have time to see the Tropics house, which has some gibbons that are neat also.
Personally, I'd recommend doing Polar Bear, Penguin, go to Africa (take the tram on the way back) and do the loop, then if time go to the tropics house on your way back. But if like, Tigers or kangaroos are your favorite animal then skip Africa.