After United's humiliating loss David De Gea's price has fallen to pretty much half of what it was before the match. As I type this post, he's valued at about 5.6. If you couldn't get him in your team before the huge loss, you might think about fitting him now.
Sure, most of us suffered from the -18.00 points he returned after the Citeh match, but now I think that he definitely becomes a season keeper. In the past two seasons in La Liga, DDG was a point scoring machine. Yes, he would return the odd negative value when Atletico played Real Madrid or Barcelona, but the other 34 matches of the season the keeper would bring in a decent amount of points. Looking at point returns so far this season for DDG, I think the trend he set in La Liga seems to continue now in the EPL. Right now looks like the right time to jump in and get DDG for the season. (Also keep in mind he got the Citeh and Chelski game out of the way in the first half.)