Telltale Games (http://www.telltalegames.com) have an offer on at the minute due to it being their 5th birthday where you can get their games for only $5 an episode. Just use the following code - KE5-MRX-LGC-SAJ
The code will work as many times as you like to use it up until June 17th 11.59pm Pacific when it will expire.
You can buy episodes from games including Sam & Max seasons 1 and 2, Wallace & Gromits Grand Adventures, and Strong Bads Cool Game For Attractive People.
EDIT - didnt know if this should go in games section or bargains and freebies. If mods think its in the wrong place then please move it.