Earlier this gen, I thought the Wii U was going to sell ~20M, however, with the announcement of their next console (rumored to be both a home console and a handheld) coming next year and nothing really on the horizon after Zelda (if that hasn't already moved onto to being cross-gen or NX exclusive), I think sales are going to drop even lower than they are, now.  I'm thinking more along the lines of ~16M, with a max  of ~18M.

Your XBO seems pretty reasonable.  Again, originally I thought it was going to end higher, much higher.  ~60M+.  But, after seeing its lows around the world, even the US, I have changed my opinion.  The only real reason the XBO has done relatively well the past few months, especially the holidays, is because of the firesales and endless deals MS has been having for it.  MS won't subsidize its sales forever.  This year will most likely be its peak year, with Halo 5 and probably the last big moneyhatting move (TR as a timed exclusive), as well as a price cut to $299 to answer the PS4 cut this year.  There's even rumors they are starting to bow out of big 3rd party advertising deals, with Sony picking up COD this year.  I'm guessing ~40M, ~42M max.

Here's where your estimates go wrong.  No market leader has sold less than 100M since Gen 5.  This gen will be no different.  Even if the PS4 peaks next year, like you believe it will, it will have a very gradual drop the following years.  2016 should be a great year and 2017 should, at the very least, come close to matching 2016 sales, since we should see the launch of the Slim (if it hasn't launched already) and a cut to $199, as well as many other 1st party exclusives from devs we still haven't heard from.  2018 should be another good year, since it will be a full year at $199, plus some great late gen games, like Sony always does.  It shouldn't be til 2019, with a possible launch of the PS5, til we see some real drastic drops.  It'll also see stronger sales than the PS3 after its successor is launched, as it's more popular and I wouldn't be surprised to see its price able to drop to $149.  I'm guessing ~125M, max ~140M.

So, with my estimates, without maxes, that gives us:

PS4 - 125M (69%)
XBO - 40M (22%)
Wii U - 16M (9%)