I think we're at the point, where you can legitimately make a case for ter Stegen being the best keeper in the world. One thing is his abilities with his feet, but his goalkeeping abilities in the more traditional sense - reactions, commanding the area, claiming crosses and defending one-on-one situations - have just vastly improved over the past couple of years.
In his first season, I definitely felt that Bravo had the upper hand in terms of traditional goalkeeping abilities, especially as it looked like ter Stegen was lacking in his command of the penalty area. At this point ter Stegen does all of those things almost as well as De Gea and Oblak - and then he's just head and shoulders above them, and in my opinion everyone else, as far as playing out from the back goes.
Right now, I think it's between ter Stegen, Oblak and De Gea. Neuer still looks hampered by his injury and is not quite at the level he was 18 months ago.