My brief opinions...
Christianity. I post this one first because there are lotsa them here...pros would be, that they tend to move in very organized institutions. They have all this hierarchy to deal with stuff, and it seems to be more or less efficient to me, I don't know. Also, they do a lot of charity work, which is nice as well. Cons? Hm, a few things like they hate 'unbelievers' intensely from what I've read in the bible. Especially the revelation, which appears to be the product of a twistd mind.
Islam? I know very little about it, it just seems ironic that a religion advocating peace should have so many terrorists claiming its name.
Hindu? Know even less so no comment. Seems nonviolent though, which is cool.
Buddhism? Gotta agree with ya there, it's totally nonviolent (except in some isolated suicide protests...like people burning themselves to death...shudder), at least toward others, and it's not hotheaded like some seem to be. Cons? It's a tad detached, the temples are mostly in inaccessible areas like mountaintops, and they seem less zealous than Christianity in curing the sufferings of others, just that "physical life is useless break out of the wheel" advice.
Atheism is not a religion however I will discuss it. It is not based on faith so it allows for unbridled, logical and scientific thought. No stupid 'moral' barriers there to stop your mind. Cons? Hard to say, since I'm atheist myself but I'd say that atheists have little source of comfort in times of crisis. No 'superior being' or religious principle to comfort you so you're forced to draw on your own strength. That's the only con I can think of, if it can be called a con.
Any thoughts?