I'm not big on labels, but you would not be wrong if you labeled me as a Soto Zen Buddhist.
While I could go on and on about why I practice Buddhism (which in my mind isn't a religion, but whatever) I'll sum up the differences between that and most religions as a contrast between faith and doubt.
I was raised Protestant, and minored in religion in college. In my life and in my studies the common denominator in the Judeo-Christian-Islamic tradition is the concept of reward for faith. Have faith in God an his chosen messenger (Moses, Jesus, Mohammed) and you will be rewarded.
What I find interesting about Zen in particular and Buddhism in general is that its not based in faith, but in doubt. The whole point of our Zazen practice is to question, literally, everything. Question authority, question society, question our community, our very understanding of the world around us. But more important than any of that...question yourself. Hold yourself accountable, don't let yourself off the hook. This is especially hard since our own internal psychological defenses enable quite a bit of self delusion to protect our ego. Through Zen we question that, and in doing so, aim to destroy this fallacy we have come to understand as, "self." If this sounds a bit like Tyler Durden's, "You are not a precious snowflake routine," that's because Palahniuk basically took a lot of Zen and formed that character around it (the ritual of leaving the space monkeys at the doorstep and berating them for two days straight before letting them in the house is straight out of a Rinzai Zen ritual for accepting new monks. I've literally seen it happen).
The Gautama Buddha's dying words to his students were, "Be a lantern unto thyself." He understood that everything needs to be questioned, even himself. This appeals to me. Anything or person that says, "THis is the definitive answer!" tends to set off BS alarms in my mind, and the fact that Zen doesn't claim to KNOW anything definitively feels honest to me. Zen practice is less about discovering the truth, then pursuing it.
So yeah, while most religion rewards blind faith, Zen rewards contemplative doubt.