UPDATE: DxO 50% Off Offer Now International
DxO has a promotion going on right now to get 50% off DxO OpticsPro, running through November 1st. You just need to enter the code WELCOMEBACKOP at checkout to get it. I've become a big fan of OpticsPro lately, as it's become my go-to alternate RAW decoder for particularly challenging files. Combined with the PRIME noise reduction (available only in the more advanced ELITE edition—normally $199; $99 with this offer). Plus if you have DxO ViewPoint 2 ($79) installed, you can access the perspective correction tools directly in OpticsPro. It makes for a great solution.
Keep in mind that there's also a bundle for all three apps, Optics Pro 10, FilmPack 5 and ViewPoint 2 (ELITE edition) for $289, and the discount doesn't apply there. If you're just interested in OpticsPro then obviously the discount is awesome. If you want OpticsPro and Viewpoint, the discount still works (total price now $178). However if you want all three apps, then the bundle of $289 is still a better price than buying OpticsPro on discount and the other two at full price (that'd be $307 total).
Check out this introduction to DxO Optics Pro video recorded by… yours truly!