Following is a list of words I have heard people misuse within the last month. My English is far from perfect, but these ones really bother me. I reference dictionary.com to confirm my usage suggestions (especially since my husband disagrees with me on several of these).
1. unique--it means one of a kind, not different or unusual
2. between vs. amongst--this one gets complicated. It differs with number of objects and intent (which is probably why a lot of people misuse it). See dictionary.com for an explanation.
3. anxious vs. eager--anxious implies worry or fearful expectation, eager is excitement
4. literally--this word means "actually" and should not be used in front of a figurative statement, i.e., "I was literally scared to death." No you weren't. If you had been, you'd be dead and not telling the story.
5. nauseated vs. nauseous--technically, nauseated is how you feel and nauseous is an adjective for something causing nausea