It's an African American slang thing. It means "wow, that's soo good!"
Example:
Girl A: I just got a job as a journalist for the New York Times
Girl B: Go on with your bad self!"
Although when most people say it it's usually said like this
"Go'n witcha bad self!"*
In my case, it means my bad self showed up this weekend and I went along for the ride.
Example:
Choice A: Scrambled egg whites with scallions and Parmesan, fresh strawberries
Choice B: A pile of bacon and Grandma's Naughty Cinnamon Balls
My bad self: Both, with extra cinnamon balls because they are so delicious right out of the oven and everyone else is having at least three so just one will be no big deal and can you please pass the cream cheese frosting?
As James Brown would say, "Good GAWD! Hit meh!"
It was a classic trap. I was roiling with all kinds of emotions, both proud and melancholic, at the same time as I was celebration baking and entertaining. When I was serving the warm blondies with homemade ice cream to the boys, I could almost feel the angel and devil on my shoulders.
Devil: Eat it! Eat your brains out.
Angel: Don't even think about it. Just have some more of that lemon mint water instead.
Devil: Yeah, right.
They were really good blondies.
Let's all burn a few extra calories laughing this morning, and then I can get GONE wit' my bad self, and get back on the program.
* This is from Yahoo Answers, so it is by no means the authoritative definition, but it works for the purposes of this post.
