It used to be that CGI in movies and TV was so low-budget, that it was ALWAYS noticeable, and horrible.

But now, they've gotten it to the point where most of the time, you have no idea there are even CGI effects in the shots!  Subtle things, like smoke, or city extension, or more people in a shot can all be done really well in CGI now.

Game of Thrones has gotten so popular now, too, that they finally have the budgets to use this amazing tech to do some great visuals for the show.  Hell, they even used it to create a single boat to float alone in a bay.  Probably turned out to be cheaper than building a boat of any scale.

Check out the before and after shots from this season's Game of Thrones CGI stuff.  Pretty cool.  Then go back and watch the episodes again to see if you can spot more.