Off the top of my head, and probably far from definitive:
Newquay: Paca, Asian Fishing Cat, Black Wildebeest, Fossa, Belted Black & White Ruffed Lemur (not a separate species, but interesting nevertheless), Philipine Spotted Deer, Visayan Warty Pig, Owston's Palm Civet (unlikely to see), Narrow Striped Mongoose, Six Banded Armadillo, Tamandua.
Welsh Mountain Zoo: Brown Bears, Arctic Fox, Andean Condor, very large Alligator.
Blackpool: Blesbok, Hartmann's Mountain Zebra, Markhor, Yacare Caiman, Mellaganic Penguin, Aardvark, North American Tree Porcupine, Arabian Gazelle, Agile Wallaby, Ground Cuscus, King Colobus, Lesser Mouse Lemur, Eastern Diamondback Rattlesnake, West African Mud Turtle.
Colchester: Geoffroy's Cat, Binturong, Aardvark, Striped Hyena, Spotted Hyena, White-nosed Coatis, Cherry-crowned Managbey, Black-backed Jackal, Komodo Dragon, Cuban Crocodile, Slender-snouted Crocodile, Warthogs, Patas Monkey, Blue Duiker, Cuban Hutia, Mandrill, Gelada Baboon, White Tiger (if that's your bag).
Newquay's a great little zoo (arguably the best little zoo in the UK), Blackpool's very good, a nice medium to large-ish zoo (it has the advantage of being built early '70's, therefore no really old enclosures, great Sea Lion enclosure too), and I like Colchester and think it's a good large zoo (great Sea Lion walk-through and you can feed (supervised) the Giraffes & Elephants) -I agree, as someone here has stated, it's a "Marmite zoo" but I know many who don't particularly like it who still concede it's a great collection.