You know this is gonna sound really, really, really lame but when I was a kid I kind of modeled a lot of myself out of Sonic the Hedgehog from Sonic Adventure 1 and 2. I didn't really make myself an exact clone, but I kind of kept his care free and laid back attitude.
The whole pony personality test thing says I'm most like Pinkie Pie, and I can understand why it'd say that. I'm usually laid back about anything, won't shut up, too busy bouncing off the walls, doing all sorts of stupid things, blah blah blah.
that being said, if I were to compare myself to an actual cartoon character I'd actually have to say Naruto. I haven't seen the later episodes because I admittedly lost cable while it was still being shown and haven't been bothered to look it up online yet, but I remember him being an immature character who wanted to do good but was usually too lazy or unskilled. This applies to me because this totally is me.