Girlfriend and I have a thing about words that are inherently funny. A brief list:
Chimp
Fang
Cutlet
Flange
Crate
Crispy
And of course, Ointment and Amphibian
You have to sort of look at them individually, with no context. Sort of meditate on them for a moment, and you’ll see what we mean.
OK, let’s have your additions to the list.
sponge
schism
gneiss
paradigm
idiom
quintal
Pickle
Tits, winkle and vibraphone!
Rotary Wankle engine…
It’s actually “Wankle Rotary Engine”, but hey.
I’ll suggest: moist.
Snausage
Belly
In many African languages, words with an unvocalised silibant and labial termination are common, while in the Indo-European languages, this combination is found in only two words in common usage:
"orgasm"
"fascism"
Countless rock stars, from Mick Jagger on, have expropriated African-American vernacular to express, in an enriching Anglo-Saxon economy, the metaphor on the condition of besmitten manhood vs. delorious womanhood, but I don’t think they will ever successfully bridge either the African/European or man/woman “chasm.”
was
such
of
asterisk
potato
episcopalian
Juxtaopse.
Obsequious.
Omniscient.
Synergy.
Presbyterian.
Hemi-Demi-Semi-Quaver. It means 8th note. 
Onomotopiea:
jism
The cognates for “orgasm” and “fascism” do not end “-sm” in most IE languages.
“chasm” is not a borrowing from an African language. It is from the Greek “khasma”.
You forgot “spasm” and all the other “-ism” words.
Bultaco, always made me think of a Mexican place, not a motorcycle company…
Supple
Gotta add my very favourite word: creosote.
Hmm, here are the rest of mine…
[ul]
[li]queue[/li][li]ululate[/li][li]orange[/li][li]moon[/li][li]orb[/li][li]toad[/li][li]frog[/li][li]gadget[/li][li]twee[/li][li]amphitheatre, amphitheater[/li][li]wow[/li][li]woofer[/li][/ul]
[sub](NOTE:Doggie’s having fun here)[/sub]
[ul]
[li]gossip[/li][li]quack[/li][li]snickersnee[/li][li]honkytonk[/li][li]buttock[/li][li]agog[/li][li]bicycle[/li][li]boggle[/li][li]welt[/li][li]goo[/li][li]plug[/li][li]pang[/li][li]bosom[/li][li]gloat[/li][li]goat[/li][li]squeak[/li][li]hobgoblin[/li][/ul]
Geez, I’d better stop now. This is one of those posts for which I’m going to keep thinking of stuff after I’ve hit submit. Curse you Grok!
Bamboozle.
Discombobulate.
Burrito. (Try pronouncing it Buh-REE-toe, accenting the middle syllable with a huuuge falsetto pitch)
M.
I’m surprised TheLoadedDog hasn’t mentioned what I have always considered the funniest word in the English language
chook
It’s so appropriate, the common slang (in Australia, at least) for a chicken. So fitting for that noble bird.
uvula
fork
stork
twig
spigot
rhythm
syzygy
yowl
Worcestershire
gnu
epithet
doodle
snot
rhino