For a brand new application, is it better to use WPF over Windows Forms? I used Windows Forms before but not much WPF. As far as I know, WPF is the successor to Windows Form
AFAIK WPF is the successor to WinForms, right?
I don't believe this is true as much as MS might like to push this. There is just too much legacy code written on Winforms for that to be a realistic thing in the near or even somewhat distant future.
So with that in mind, if you would like to, and can afford to spend the time learning WPF I would do that. Otherwise I would use Winforms.