Madglibs has a long list of Mad Libs, including some that are literature based (I used one from "The Raven" when I taught Poe) and others from pop culture or everyday life. The site has a form, so the teacher can call on people to add to the list and type it in. I also used it to reinforce lessons on parts of speech without just giving my study hall crowd more grammar worksheets.
These logic puzzles and lateral thinking problems are real head-scratchers, and they really helped get my class debating on the answer, especially when a small prize from my prize bin was at stake. They're good lateral thinking problems, and they're so satisfying when you finally figure them out.
If you want a physical worksheet of brain teasers, this site generates one with whichever brain teasers from the site's bank you choose. This could be a great thing to have in an "I'm done, now what?" bin, as a part of a holiday packet, or as part of a reward of free time in the class.
This document has a list of mathematical and spatial reasoning puzzles that require a bit more preparation than some of the above brain teasers. It's still a great way to teach lateral and spatial thinking, which can be a fun yet educational way for students to pass the time.