Ursus Arctos Arctos because I love the fact that the continent is named after a (different), um…, “ursus” and not the other way around.
Also gorilla gorilla gorilla gets points for not being a bison.
Whoa! +1 trivia.
Upupa epops is definitely one of my favorites. But Ajaia ajaja, the Roseate Spoonbill, is also quite euphonious. Spinus pinus, for the Pine Siskin, is also rather nice.
Zyzzyx chilensis, a sand wasp, sounds kind of buzzy.
Zimmerius vilissimus, the Paltry Tyrannulet, is a very small, boring, gray bird. The specific name means “most vile,” no doubt bequeathed by a frustrated ornithologist after a long day sorting through trays of nearly indistinguishable little flycatchers.
And the wren is called a cave-dweller because it often puts it’s nest in a hole in a wall or a crevice.
Then there’s the Chimpanzee Pan troglodytes, after the god of the wilderness and its supposed cave-dwelling habits.
Metasequoia glyptostroboides. Dawn redwood. I just like saying it.
From the article:
“Many people see ‘Jethro Tull’ PP18789 as an improvement over ‘Zamfir’ since its petals are more consistently fluted…”
I don’t care who you are, that’s funny right there! 
Trillium erectum is a nice one. I’ve often thought that if I were to take a hippie name, it wouldn’t be Willow or River or Silverwolf Ravenmoon, but just the simple Trillium.
One that always makes me giggle is Marrubium vulgare, or horehound. When in herb school, I’d remember it as “you marry a bum, you’ll get vulgare* from some whore hounding him…” 
*Not a real thing, but it sounds like a venereal disease, doesn’t it?
I did once scream in the car: “Xanthocephalus xanthocephalus!” It was true, but not helpful to those around me.
Ipomoea quamoclit, the cypress vine I’ve grown for decades, and Corvus cristatus, name for the bluejay in Audubon’s day.
I almost forgot:* Dracorex hogwartsia*. The Hogwarts dragon. It’s a recently discovered dinosaur from the late Cretaceous, and the skull is here in Indianapolis, at the Children’s Museum (which is a surprisingly good museum, even for adults, if anyone is ever in Indy for some reason and has some time to kill). Of known dinosaurs, this one really (probably) did bear some resemblance to legendary dragons.
I like “Lama glama”.
An extinct vampire bat, quite a bit larger than any existing vampire bats, was named Desmodus draculae.
A colleague of mine named a bolas spider, which catches prey by throwing a sticky ball of webbing at them, Mastophora dizzydeani after the baseball pitcher. I’ve always loved him for that.
Aplatophis zorro, the Snaggle-toothed Snake-Eel, was named by a another colleague after Zorro because of the Z-shaped marking on its cheek.
I came in to say this one! And I actually have gotten to use it a couple of times - there is one in the main park in my hometown, and there was one on my college campus.
When I looked up that spider, I found a link to this interesting Wiki list:
Hey, that was my one! You’ll have to share it.
Boops boops - although the actual pronunciation (bo ops bo ops) is less fun that ‘boops boops’, it’s still fun to say.
As a confirmed chocoholic I like it that the tree that produces the cocoa bean is theobroma cacao, which means, in Greek, “food of the gods”
Accelerati incredibilus and Carnivorous vulgaris …