LOL like words that give you a temporary speech impediment. there's only a couple for me.
i can't say aluminum really fast, linoleum, orgy (i always say it wrong), parentheses and free throw. i always end up saying three frow no matter how hard i try. ._.
how about you?
supercalifragilisticexpialidocious.
i have trouble saying innate, demonstrate, and bass (i always say bah-ss when talking about the instrument). but then again, i'm french. i don't really care. <:
I remember when I couldn't say enemy or anemone without pausing to pronounce it slowly XD
I still can't.
I don't like saying "genuine" because I think I stress the wrong syllable. Or something. Also apparently I say "museum" wrong :( According to my boyfriend.
edited
birthday. i can say birth just fine. but adding that d right after makes it sound all gross.
I don't think I can't pronounce any words, but probably in a week I'll find something out.
My friend can't say calculator, though. She can say it slowly but altogether it comes out as "calcalator."
lol. TURKEY. i said it like "churkey". i had speech problems as a young child. :( i also say kitten, mitten, button and pretty much every word that ends like that with a huge emphasis on the ending so i say like KITTIEEEN. it makes me sound slightly southern.
I never had a problem with a word. The most word I can't say really good it's birthday :(
Polish, as in the nationality like.. poland. I always say paw-lish instead of poe-lish.
preemptive. wtf is up with this word anyway. it looks like preem-tive to me but apparenly it's pre-emtive like you were about to say empty.
i do spoonerisms a lot too.
remember = member to me.
Hospital xD Yeah, I usually miss out the 'H'
I say clothes as close too, but I never knew that was a big deal... I just realized I cannot pronounce it with the th.... shit.
I always have to pause to say sociology. Is it so-see-ology? Or so-she-ology? D; I always switch between those.
I used to say southern as south-ern instead of suh-thern, but I got yelled at a lot so I began to pronounce it correctly.
I also say aunt as awnt instead of ant, but that's an accent thing I think.
EXCLAMATION POINT
i will always always always say 'explanation point.' no matter what :(

hitherto D: what kind of a fuckin' word is that?!
also 'to burgeon' i say like 'dungeon'
Exhibition. No matter how hard I try, I just can't pronounce it right x.x
Month lmao.
The TTTTHHHHHH at the end screws me up. Hate that word and avoid using it as much as I can. I seriously make the "th" sound like another word. xD "mon THHHHH". D:
DEPTH. :(
I always say Death or Dept. Or if it's plural, depthe ss. (like two words) IT'S SO CONFUSING.
When I talk really fast, I usually end up saying "what" as "was". It's annoying. xD Also, I slip up a lot when I try to say lisp. I either say it as lithhp (because, you know, my imaginary lisp LOVES to pop up when I try to say it), or I actually say it right. xD