Hangman - Fun graphics, more advanced word list. (3 stars)
Halloween Hangman - Good, simple hangman game for Halloween (3 stars)
Halloween Pairs Game - Zoomable and very easy to use (4 stars)
Halloween Word Search - Good interactive word search. Might be a little small to use (3 stars)
Stacking Pumpkins Game - Might be a fun way to reward your students (3 stars)
Halloween Math Games for K-6 - Great games courtesy of the Oswego City School District
The Hallowman House - A hangman-type game for Hallowe'en (middle / high)
PBS Kids Halloween Collection - Lots of games and activities from PBS Kids.
Spelloween - Practice your spelling by identifying correctly and incorrectly spelled words. You may want to bypass the part that asks you to type the word correctly since this is difficult to do on the SMART Board (middle / high).
Frankenbrain - Find the brain if you dare! (primary / middle)
Halloween, Halloween, What do You See? - Primary reading activity based on the famous book series (primary)