How to obtain the ViewPoint

One way is to set a symbol equal to the initial default viewpoint.

v = Options[Plot3D, ViewPoint][[1, 2]]

(* {1.3, -2.4, 2.} *)

Use that symbol dynamically in the plot. Monitor the dynamic value of v and note the value when the rotated plot is pleasing to you:

Plot3D[
 Sin[x + y^2],
 {x, -3, 3},
 {y, -2, 2},
 ViewPoint -> Dynamic[v]
 ]

Dynamic[v]

 (* {2, -0.9, 2.5} *)

Here is how you can extract the ViewPoint family options from a graphic after interaction. Once you have the options, simply do a copy-paste them in the initial code :