Dr.Vita on 19 February 2015
What do you think will sell more lifetime?
Playstation Portable has currently sold ≈81M Global and won't sell anymore.
Xbox One has currently sold ≈11.5M Global and has still at least 5 years to sell.
My guess:
I think it will be a very hard fight where Playstation Portable will win.
I can see Xbox One doing:
40M in North America (X360 did ≈48M)
25M in Europe (X360 did ≈26M)
10M in Rest of the World (X360 did 9M)
0.3M in Japan (X360 did 1.7M)
This means the Xbox One will do ≈75.3M Global and Playstation Portable will be bigger!
