Long lonely nights :)
I was raised Catholic (that seems to be the case for many here) and I went to church and prayed and did the rosary with my mom and all of it. But, somewhere around High School, I looked around and realized how much bunk it was. I just started questioning everything and that broke it for me. I went through quite a long "angry atheist" phase due to my youth...ness.
But, since I am curious about all things and everything, my mind never stopped working at the whole idea of it. The whole of the universe is too big. The rabbit hole is too deep. It all started somewhere, somehow and so I can't completely discount a Creator of some kind. And perhaps there's another Creator behind that one and so forth. And that's cool. I'm just talking about the local one.
So, agnostic. Massive alien computer simulation of the universe? Sure. Magical being that created everything in a cauldron? Sure. Why not?
Will I ever call whatever it is a god? No. Do I think what we humans call God (or whatever term your religion uses) exists? No, I think we're just wrapping our fear of the unknown and the need to explain the unknowable into something that we can comprehend. We don't like unanswered questions and we're afraid of dying. That's fair.
Just because there may be a creator, doesn't mean they/it/he/she could even see us. Perhaps they just see the complex motion of the atoms of which we're comprised without seeing our bodies. If they even noticed our tiny planet in the vast, dark emptiness of space.
Also, I have a counter-point to some things that people have mentioned. The whole "I met some great people..." Before I had completely changed my mind, I was at a late night youth church group thing. They had us all separated in pews and these older kids or adults came to speak to each of us. They dug fairly hard in finding what was painful to us (the way I was abused by my brother in my case) and then sold religion fairly heavily using that pain. I cried when it was my turn and, at the time, it felt great. Some time afterwards, I realized what had happened and, yeah. I was, uhh, fairly angry. I think, if anything, that solidified my views.