What's your favorite unorthdox opening to use?

What is that? I've not heard of it.

I can't really explain it very well, it's kind of like your begging white to attack your king straight out of the opening. There's a couple of annotated games at gameknot.com and are better at explaining it than I am:

Game 1 Game 2

Choose "interactive" mode, it's a little easier to follow that way.

London system. Screw the people who refuse to play an opening that died in the 1930's.

I like to be use Bird Opening and Cabbage Formation...

I love the Bird and Saragossa Openings.  The Saragossa is 1. c3.  I'm an avid Caro-Kann player and so I like its chances of transposing into a Caro-Kann like setup for white if black plays 1. e5.

I also like the Hippo Defense as both white and black.  I had a string of games a little while back in live chess where all I played was the Hippo and I won more than I lost.

For the past few years, I have played about 100 Jerome Gambits, 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7!?.   Rick Kennedy has a blog on the Jerome Gambit at http://jeromegambit.blogspot.com/ .  I try to experiment with every possible gambit and unusual openings.  Lately, I have been playing 1.a4, followed by 2.b4 if I can, or 1.a4 and 2.Nf3.

My favorite as Black is the Borg gambit:

Lately I have also come to like this:

And if possible continue with ...e6, ...Ne6, ...g6, ...Bg7

I like the Grob, but avoid the gambit variation because hours of OTB analysis has demonstrated to my satisfaction that a decent player of the Black pieces will always emerge better off by capturing the pawn on g4 on the second move (assuming 1. .. d5). In my opinion, after 1. .. d5, 2. h3 is necessary in order for the opening to work.

I play the Grob like this :

I also like to play Gedult's, because Wikipedia calls it the "worst possible opening move by White."

Nothing beats the Barnes. I've got a nice 3-4-0 with 1.e4 f6: