The whole Paradox catalogue is 40% off, and there are daily deals for upwards of 75% off. The first daily deal is Victoria II 75% off, which I'm off to buy right now!
http://www.gamersgate.com/games?prio=relevance&q=paradoxsummersale
http://www.gamersgate.com/games?prio=relevance&q=paradoxsummersale