Female Gardevoir would be the obvious choice (for a male / certain females anyway)
They sense your emotion and link up with it so as long as you're happy they're happy. They also happen to be the most humanoid and feminine looking pokemon of the bunch (unless you count pokemon like Jynx, Gothitelle or Lopunny).
That doesn't necessarily mean you'll get nasty with her, though. The fact that she's humanoid would make many other things a lot less awkward. Like the wedding ceremony itself.
"You may kiss the bride"
*gets down on knees to kiss Bidoof*
^ My point right there :P
My thoughts exactly!
I'm not easily impressed; I'm usually oblivious to whatever's in front of me.