I was originally going to use the games from this site as part of the free weekday project, but then thought as most community members have already downloaded everything they want from there over the last 18 months since I first posted details of a few of the games; I thought I'd just mention new ones that appear (which seems to happen on about a monthly basis).
There has been a new match three tetris like clone released called Rhombis:
http://www.gametop.com/download-free-games/rhombis/
Please note that all gametop games open up your browser when you close the game down. However, I've checked all the files for viri and other malware and they are all clean. The browser isn't being hijacked in the literal sense as once you close it down that's the end of it, until you next play a gametop game