There are some words that are just fun to say. They have a good “mouth feel”, like the sensation you get when you bite into a taco or a handful of peanuts. Regardless of their meanings, they just plain feel good to say.
Effluvium. Fallopian. Crennelation. Ooh, that was fun! Vituperousness. Assclown. Squint. Squirt. Machicolation. Whoopee!
What are your favorites?
Caribou
Erogenous zone
Egregious. Mastication. Felonious. Thespian.
Mellifluous
loquacious
defenstrate
adamantine
Egregious
Felicitous
Conflagration
Ameliorate
Ennui
Esoteric
Facetious
Eclectic
Faux-pas
Coup d’etat
Do stolen French words count?
Fecundity
Meatware
matriculate
ubiquitous
efficacious
pontificate
opine
I love all the words that end in -ate I once compiled a list of all the ones I could think of. I had a few pages before I decided to get a life.
Bloviate. Especially in these windy political times.
Just about anything in Yiddish is a good word. “Farkakte” ranks very high among my all-time favorite human creations.
Curmudgeonly
Irascible
Peripatetic
Serendipitous
Egregious (mentioned already, but i like it)
and
Cunt 
Good mouthfeel on that one, I’d say! :eek:
All of the aforementioned words are very cromulent and they embiggen us all!
cunnilingus
gravitas (anyone?)
I like “limpid” and “lugubrious”, if for no other reason than they do naht mean whachoo thik they mean.
Oh yeah. As well as being both the ultimate insult and the ultimate “sex me up” word.
Acetylsalicylic.
Those 7 syllables just roll off the tongue! 
I always had a deep fondness for words ending in -uous:
ambiguous
contemptuous
continuous
deciduous
fatuous
impetuous
inconspicuous
mellifluous
superfluous
tempestuous
vacuous
virtuous
The more you look at 'em, the weirder they seem.
Although my current favorite word is ‘fuliginous’.
Onomatopaeia.
Constantinople.
Boat.
*Diaphanous *
*Gonorrhea * is far to pretty a word to be such a nasty thing.