At first I wanted to mention Ruckman, but then I changed my mind and so the software that I'd like to nominate would be...
Wind & Water: Puzzle Battles !
Because I really like the team and how much effort they have put into making it the great game it is, and even add that little extra by making sprites out of the buyer that they can put into the game, internet rankings and forums.. It simply is the best there is if you ask me. (I love puzzle games too)
(sorry about the links, forum problem. I'll edit when it works again)