On their own, Catch Phrase and Taboo are already pretty great word games; they really make students reach outside of their common vocabulary and think creatively to express an idea or concept. I'd often bring in my own copies of these on "educational celebration" days to help justify the day. Because every day is a day for learning, right?
You could adapt these to your classroom subject matter. I have to admit, this is not something I got a chance to do, so I can't say for sure how well it worked. But I planned to!
Catch Phrase would be a little less time intensive, since if you were to make Taboo cards, you'd need to come up with a list of words that can't be used for each one. So let's stick with Catch Phrase for now...
You could take any unit -- well, okay, this probably works best with a literary unit. If someone has an idea to adapt it for grammar, enlighten us! I'm not that creative at the moment. So, literary unit. Make cards listing names, ideas, etc. from the unit you're reviewing. That comprises your prep.
Split students into teams of at least two -- you might need to have simultaneous games going on in the room, depending on your size. I'm guessing that this wouldn't work well with teams bigger than 8 people, max. Get yourself a timer -- if you have a version of Catch Phrase, just bring in your own and use it as a timer (and for goodness sake, if you don't have a version of Catch Phrase yet, just go get one. For shame); the timer is set to random intervals, which just shakes things up a bit.
Set the cards in the middle. Form the two teams into a circle; each student should be next to members from the other team. Start the timer. On a turn, a student must get his team to guess the word on the card. The prompter cannot say "rhymes with...," "starts with the letter...," or gesture. The prompter cannot say any part of the word until one of his team members says it (i.e. if you're trying to get a team mate to say "Boo Radley" and they've already said "Boo," the prompter is now free to say his name also.) Once the team guesses the word, the student should say "Yes!" (or you can choose some other victory cue) so that the next player knows to draw a card and begin the process all over again. Keep going around the circle until the timer buzzes. When time runs out, whoever is currently playing loses that round and the OTHER team gets a point. For example, Kyle on Team B is trying to get his team to say "onomatopoeia" before the timer buzzes. It goes off, but his team has not guessed correctly yet. Team A now receives a point. Start the timer and begin again (play moves to the next person; do not start the round with Kyle). Play until one team wins 7 points...or however many works for your classroom.
Taboo would essentially be the same concept, just that you must come up with a short list (4 total, I believe) of words that the prompter cannot say when trying to get his teammates to guess the word.
If you have ideas for how to adapt these games to grammar, let me know! Or if you have other games to share, please spread the wealth!