Wicca
After I decided that Catholicism (and Christianity in general) was not the religion for me, I called myself both an agnostic and an atheist for a while. Then, around 1997, I stumbled across some Wiccan pages on (where else?) the Internet. Wiccans do not try and convert people--actually for many years, Wicca was a closed religion with secret covens, and membership was by invitation only. But this reluctance of active conversion attracted me. If I wanted to explore Wicca, no one was going to try and force me to accept it as my religion. And as I found out more information about it, I liked it more and more. Honestly, I felt lonely not believing in anything, just because, as of our current discoveries, we are all alone in the universe. And the universe is, well, pretty big ;)
Essentially, I was drawn to Wicca because it accepts everyone. I don't really relish the Judeo-Christian version of God who is so restrictive on people's personal lives, with his commandments and his covenants, and his rules and regulations. There is no 'Book of Wicca'. There is the Wiccan Rede, but that is really an informal skeletal set of 'rules'. In Wicca, you are free to practice alone (solitary) or with a group (coven). Inside or outside makes no difference; there is no church building. (Though outside is preferred; Wicca is a nature-based religion.) The God and Goddess don't control the lives of humans; they are essences and are manifested inside everyone.
The general gist of Wiccan faith is as follows: In the beginning, there was One, the Deity, and the Goddess and the God are two halves. They are not physically real beings; they are more like ethereal manifestations in one's inner self. The Goddess' symbol is the Earth, stagnant, never changing; she is the Earth and every living and nonliving thing on it are part of her. The God is symbolized by the sun, constantly changing. They balance each other out, but neglecting one or the other creates an imbalance in our world. There are other deities that factor in, and they are loosely based on what is known about Irish Celtic deities. They are acknowledged mainly as different aspects of the God and Goddess.
Wicca is a life-based religion. By that, I mean it is purely concerned with living life to the fullest, while respecting the Earth. Reincarnation is generally accepted to happen after death (not like the Buddhist version of it, with karma factoring in) but it's not a big focus. Wicca is concerned with the present, with life and nature itself, enjoying it, relishing it, and (at the risk of sounding like a guidance counselor) living to your fullest potential.
HOWEVER, though I thought for a time that Wicca was what I needed spiritually, the death of my grandfather a few years ago made me realize that it was not doing for me what I needed to have done. Does that make sense? It was the first time that a really close family member had died and even though I was 19 years old, I had no idea how to deal with death. My family is not very open in the communication-of-feelings category, and anyway, I was five hours away from them at college, so I had to basically deal with it alone. The whole wake/funeral situation was strange/surreal/horrible and did NOTHING for my personal closure or understanding of death. All I can say is that I never want to go to another funeral again in my life. Never never never never never never never.
Essentially, that death left me feeling lost and unresolved, and Wicca, which doesn't focus much on anything death-related, did not assist me in dealing with this--it didn't offer me the comfort/explanation/security/questions that I needed. I just kind of tumbled around in life for a while. I needed spirituality that would help me deal with myself, help me resolve inner turmoil, and that would satisfy me in every situation. Otherwise, what is the point of having spirituality if it can't help you help yourself when you need it most? So there went Wicca.