[landyman]

My favorite words for stumping everybody are: lynx and eczema. I thought for sure that 'lynx' would get on that list since there is only a "sometimes" vowel and an 'x' in there.

[lotharbot]

I'm a big fan of words that use w as their only vowel, like crwth, cwm, and pwll. Pwll is especially good because even if they get P and L, most guessers will go through any common vowels they haven't yet tried, and run out of guesses before they even consider W.

[ja27]

If I ever get divorced it's going to be due to my insistence that I was correctly taught "a, e, i, o, u and sometimes y and w" as my vowels.

[tokenadult]

I don't know Welsh. What is the pronunciation of "Pwll"?

[JoachimSchipper]

Guessing l and/or n isn't too unlikely, and there aren't many words that look like l.n.; I think that explains why lynx doesn't do so well?

[jcl]

Or that a player will plow through all the vowels early, and -y-- doesn't match many words.

[spoondan]

I like "queueing" for its long run of vowels. It's not terribly difficult to guess, but does tend to confuse people.

[vault_]

Also good are nymph, zephyr, and syzygy.

[scdlbx]

phlegm works fairly well, too.