I'm reading The Hobbit to the girls at bedtime, and then reading the annotations from The Annotated Hobbit after they go to bed. The author, Douglas Anderson, recently wrote about an old book he found titled What’s the Name, Please? A Guide to the Correct Pronunciation of Current Prominent Names.

I immediately found a copy on archive.org and skimmed through looking for familiar names. Here are the names that I've been pronouncing incorrectly:

Willa Cather
Rhymes with "gather"
You ask for the name of Lord Cholmondeley: / I ponder the matter quite dolmondeley; / For surely you know it, / And don't need a poet / To tell you it rimes well with *comely*.
Padraic Colum
pau'drig column
W. E. B. Du Bois
dew boys
Lord Dunsany
Mohandas Gandhi
mo-han-dahss gahn-thee
Vladimir Horowitz
Alfred Knopf
Rhymes with "tassels"
Emmuska Orczy
em'moosh-ka or'tsey
Thomas Taliaferro
John R. R. Tolkien
P. G. Wodehouse

Also of note, the epigraph is a few fun lines from the poem "The March to Moscow", poking at the difficulty English speakers have with Russian names:

And last of all an Admiral came,
A terrible man with a terrible name,—
A name which you all know by sight very well;
But which no one can speak, and no one can spell.