I use all of these as quick warm-ups with my high school English Club and for teacher's workshop sometimes. I just do a few slides each time I use it.
Brainteasers - this is a class favourite. I played it as a full game... the first team to write the answer on the board got a point. Only a couple required hints.
Riddles
English Mistakes
Word Ladder - how many words does it take to get from 1 word to the next by changing 1 letter at a time only