11 Words Adults Just Can't Spell | Jonathan Anker, digtriad.com

I think this is a pretty good list of words to think twice about. As Anker says:

Here are 11 words that many adult screws up, presented for you in standard spelling bee form.

The word is: Occasion ...
The word is: Fiery ...
The word is: Embarrassed ...
The word is: Restaurant ...
The word is: Vacuum ...
The word is: Loose ...
The word is: Daiquiri ...
The word is: Independent ...
The word is: Recommend ...
The word is: Separate ...
The word is: Misspell ...

I usually give at least a second thought to a couple of them: occasion, misspell. (Misspell is an ironic word in this list.) Of course, none of them should be capitalized unless they begin a sentence or are in a title or part of a proper name.

For more resources on spelling check out the Spelling section in Garbl's Word Links.