My list is probably quite unique, but I'm focusing on animals that are mostly fairly different from what we currently have in game. I'd love to see animals like Swans swimming around guest areas and more aquatic animals in general, along with flightless birds.
Here's my wishlist:
1. Platypus
2. Walrus
3. Great White Pelican
4. Atlantic Puffin
5. Secretary Bird
6. Green Sea Turtle
7. Bottlenose Dolphin
8. Mute Swan
9. West Indian Manatee
10. Grey Crowned Crane
11. Shoebill
12. Goodfellow's Tree Kangaroo
13. Tasmanian Devil
14. Emu
15. Quokka
16. Raccoon
17. African Crested Porcupine
18. Marabou Stork
19. Common Wombat
20. Musk Ox
21. North Island Brown Kiwi
22. Saiga
23. Makhor
24. Asiatic Lion
25. Wolverine
I must add to this that I am very much in the camp that would like to see both aviary animals and fully aquatic animals. I think these would diversify the game, bringing some truly game-changing mechanics that would revive the community. Whilst I really appreciate the conservation message for the game, I think the marine animals, in particular could be brought in with more of a 'sanctuary' - animal retirement and rehabilitation than an entertainment focus. Guests could still visit this and it would be in fitting with the game's ethos. My caveat in this is this wouldn't include large animals like whales for me, but would include smaller animals like dolphins and sharks.
In terms of this, including to support current animals I think it is essential that we need an official solution to underwater tunnels to be implemented in game, which having conducted a poll on Reddit, proved a very popular suggestion.