What are some words commonly mispronounced? (Not by elision/reduction (like ה׳→אדְני) or assimilation (like תזכרו→תשׂכרו), but rather words that are pronounced wrong simply because that's how people think they should be pronounced.) I'm excluding from this request errors in stress (emphasis), as those are, alas, too numerous to list. I'm including, however, words mispronounced in a person's own dialect (הברה), though others would consider them correctly pronounced. And I mean any "Jewish" word: a word relevant to, and mispronounced in, Jewish life, be it Hebrew, Yiddish, Aramaic, or other.
Often the problem is we see a familiar-looking word and our brains assume it's the word we know, rather than sounding it out carefully as it may be slightly different. E.g. a word that looks just like "edosav" but is actually "edvosav."
The best example that I know of, though, is when the Chazzan takes the Torah back on shabbos; the congregation chimes in with "Hodo al eretz v'shamayim"; "His glory is on the earth and heavens ...". Unfortunately the word "hodo" is less common in our prayers than the word "hodu", give thanks; I usually hear about half the shul saying that. (Maybe it's just my hearing?)
Then there's the fellow who would do Psukei D'Zimra every day and say "v'yimalei ch'vodEE es kol haaretz, amen v'amen." ("may His glory fill the Earth" -- just with my instead of His.) Heh.
ספר ישׁעיה פרק מ פסוּק לא וְקוֹיֵ ד' יַחֲלִיפוּ כֹחַ is often mispronounced as וְקוֹוֵי ד' יַחֲלִיפוּ כֹחַ
Has anybody else noticed that many people attempting to sound "Israeli" or "Sephardi" often pronounce a Kametz as a Pata*h even when it is supposed to be pronounced as a Kametz Katon?
Worst examples are: "Kal" instead of "Kol" - I mean, come on, couldn't they at least pronounce it like Ashkenazim and say "Kawl"?
"Karban" instead of "Korban" - I have not heard many people make this mistake, but I have heard it a handful of times. It makes me cringe.
"Le'Avdecha" instead of "Le'Ovdecha". :(
"Kadshecha" instead of "Kodshecha". This one actually makes me want to cry.
Bitya Bat Par'o instead of the common mistake of Batya.
Da-ni-yel instead of da-ni-el
ברוך הוא אלוהינו שבראנו לכבודו should be pronounce sheb'ra'anu (that He created us) and not she'baranu (that we created)
and a biggie. people say Ha'shem (with segol) instead of Ha'sheim (with a tzerei) causing a subtle but fundamental difference in connotation between it sounding like a personification of a person's name (Hashem said this and Hashem did that) versus the way it should be taken, a non-physical third-person entity: THE NAME.
The second pasuk in Sh'ma: ואהבת את ה' אל-היך... V'a-hav-ta should be pronounced mil'ra, not the almost universal "V'a-hav-ta". This is serious, because it actually changes the meaning - it should mean "and you shall love Hashem your G-d", whereas the mispronunciation renders it "and you loved Hashem your G-d". Reference: Rabbi Phil Chernofsky of Torah Tidbits.
I always cringe when someone replaces the "Ve" ("and"/flip to future) before a verb with the "Va" ("and"/flip to past) they're expecting.
One example of something similar: In Havdala (words are from Esther, but ba'alei keriya are less likely to make this mistake), saying "... vesasson vayekar" instead of "... vesasson vikar."
Look at this question: Why do many (most?) people call the upcoming holiday “Peysach”?
"דּוֹר לְדוֹר יְשַׁתַּבַּח מַעֲשֶֽׂיךָ" instead of "דּוֹר לְדוֹר יְשַׁבַּח מַעֲשֶֽׂיךָ" in אַשְׁרֵי "
כִּי גָז חִישׁ וְנָּעֻֽפָה instead of "כִּי גָז חִישׁ וַנָּעֻֽפָה" in תְּפִלָּה לְמֹשֶׁה in psukei dzimra of Shabbos.
"נְרַנְּנָה בִּישׁוּעָתֶֽךָ, וּבְשֵׁם אֱלֹהֵֽינוּ נִגְדֹּל" instead of נְרַנְּנָה בִּישׁוּעָתֶֽךָ, וּבְשֵׁם אֱלֹהֵֽינוּ נִדְגֹּל in לַמְנַצֵּֽחַ at the end of shaharis weekday.
"וְאוֹמְרִים פְּעָמִים בְּכָל יוֹם" as opposed to וְאוֹמְרִים פַּעֲמַֽיִם בְּכָל יוֹם before korbanos everyday.
וָאֲהַלְלָה instead of וַאֲהַלְלָה in אַשְׁרֵי
חַלָּמִישׁ לְמַיְינוֹ מָֽיִם instead of חַלָּמִישׁ לְמַעְיְנוֹ מָֽיִם in הלל
וָאַשַׁלֵשׁ instead of וַאַשַׁלֵשׁ in רבוֹן כל העלמים said Friday night before אשׁת חיל.
Instead of כִּי כָּל אֱלֹהֵי הָעַמִּים אֱלִילִים I hear some people constantly say כִּי כָּל אֱלֹהֵי הָעַמִּים אֱלֹהִים in hodu of psukei dzimrah!
Even worse... וַיִרְאוּ הָעָם אֶת ד instead of וַיִּירְאוּ הָעָם אֶת ד!
Can it get any worse? Yes! Baruch Hu Elokainu Shebaranu Lichvodo instead of Sheb'ra'anu Lichvodo!
and for now last but certainly not least one of my all-time favorites...
Instead of וּבָרֵךְ שְׁנָתֵֽנוּ כַּשָּׁנִים הַטּוֹבוֹת one guy I hear all the time says וּבָרֵךְ שְׁנָתֵֽנוּ כַּנָּשִׁים הַטּוֹבוֹת!
I have many more and can go on and on and on...