The DeLadysigner gathered votes from 2500 Planet Zoo players about their top 20 favorite PZ animals, and made the top 100 most popular species. Here is the list from the lowest to the highest:
100. White-and-White Ruffed Lemur
99. Wolverine
98. Indian Peafowl
97. Prairie Dog
96. Red-necked Wallaby
95. Dingo
94. North Island Brown Kiwi
93. Reindeer
92. Spotted Hyeana
91. Little Blue Penguin
90. Scimitar-horned Oryx
89. Wild Water Buffallo
88. Baird's Tapir
87. Babirusa
86. Colombian Capuchin
85. Llama
84. Galapagos Tortoise
83. Red Kangaroo
82. Beaver
81. Nine-banded Armadillo
80. American Bison
79. Dwarf Caiman
78. Three-toed Sloth
77. Striped Hyeana
76. Ring-tailed Lemur
75. Greater Flamingo
74. Badger
73. Gharial
72. Siamang
71. Malayan Tapir
70. Somali Wild Ass
69. Bongo
68. Zebra
67. Egyptian Fruit Bat
66. Mute Swan
65. Fossa
64. Wombat
63. Aardvark
62. Axolotl
61. Emu
60. Crane
59. Arctic Wolf
58. Gorilla
57. Polar Bear
56. Caracal
55. Crested Porcupine
54. Pangolin
53. Indian Elephant
52. Lar Gibbon
51. Sun Bear
50. Puma
49. Saltwater Crocodile
48. Cassowary
47. Fallow Deer
46. Black Rhino
45. Grizzly Bear
44. Common Hippo
43. Red Deer
42. African Wild Dog
41. Sand Cat
40. Binturong
39. King Penguin
38. Alligator
37. Red River Hog
36. White Rhino
35. Orangutan
34. Giant Anteater
33. Moose
32. Raccoon
31. Koala
30. Pygmy Hippo
29. Grey Seal
28. Eurasian Lynx
27. Komodo Dragon
26. Reticulated Giraffe
25. Okapi
24. West African Lion
23. Cheetah
22. Timber Wolf
21. Siberian Tiger
20. Red Fox
19. Arctic Fox
18. California Sea Lion
17. Snow Leopard
16. Giant Panda
15. Bengal Tiger
14. Clouded Leopard
13. Przewalski's Horse
12. Meerkat
11. Giant Otter
10. Amur Leopard
9. Platypus
8. African Savannah Elephant
7. Maned Wolf
6. Fennec Fox
5. African Penguin
4. Jaguar
3. Red Panda
2. Asian Small-Clawed Otter
1. Capybara
Compared to the META wishlist in the Frontier forum, some least demanded species in the Frontier forum did make on this list including Asiatic Buffalo, Giant Otter and Dwarf Caiman, also some top-demanded species in the Frontier forum are low ranked in this list, like Wolverine and Kiwi, or even do not make on the list at all such as Tasmanian Devil and Takin. Seems like this vote tends to reflect the opinion of general players who are not animal-nerds.
There are 37 Artiodactyla species in the current game, but only 15 of them appear in the list, which is lower than 50%. The Frontier is bovid-lover and offers 20 bovidae species, the family with the greatest number of species in the game. Ironically only 4 of these 20 bovids come to the top 100 popularity and none of them on the top 50 (the most popular Bovid is Bongo which ranked #69). I am also surprised that Asiatic Buffalo comes to the list since it is completely absent in the captivities, those "realistic gangs" shouldn't like this species though.
By contrast, there are 42 Carnivore species in the game and 37 of them are top 100 popular. The only 5 absent are mostly bears (Formorsan Black Bear, Sloth Bear, Himalayan Bear), plus Dhole and Skunk. Even Dingo can make on the list, probably general players just think "oh such addorable doggy" rather than "damn, another copy & paste of Timber Wolf". Only 6 species in top 25 are not Carnivore. But I am also surprised that Giant Panda is just ranked #16, even below Przewalski's Horse. In real life zoo, I don't think P-Horse is more attractive to visitors than Giant Panda.
This vote probably reflects why the Primates are neglected in the game, 6 of 13 Primates are absent from the list, the most popular Primate is the Orangutan, which is ranked #35, so no any Primate in the top 25.
The lack of birds is the major complaint that has continued throughout the years, 10 of 11 birds in the game do make in the list (the only one absent is Ostrich), but only 1 bird in the top 30, the African Penguin.
Unsurprisingly majority of exhibit species are absent, only 3 of them did make on the top 100 which are Sloth, Axotol and Egyptian Fruit Bat. The Axotol is the only terrarium species on the top 100, which makes the Conservation pack the only pack that has all of its species on the top 100.
The newly-released Eurasia pack has 6 species absent from the list, I am somewhat surprised that Takin is absent