The best replacement for wpf is windows forms.

The best alternatives to wpf are rated as following:
★★★★★  windows forms
★★★★★  winforms
★★★★  silverlight
★★  forms
★★  html5
★★  asp.net
★★  mvc
★★  wcf
★  qt
★  mfc
★  winrt
★  windows forms application
★  asp
★  swing
  asp net mvc
  silverlight 4
  directx
  windows form application
  winform
  javafx
  windows store
  gdi
  windows application
  win32
  xaml
  metro
  xna

Your alternative for wpf is not listed? Suggest!
Speaking about wpf, one probably shouldn't forget about mvvm.

Other search terms related to wpf and their ratings are:
★★★★★ mvvm
★★★ c++
★★★ xaml
★★ wcf
★★ entity framework
★ expression blend
★ window border
★ databinding
★ mvc
★ binding
★ windows forms
★ ado.net
f#
window
directx
You have in mind a companion for wpf and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of wpf in all years. Click on graph for more.
wpf
windows forms
winforms