I have a moissanite ring - got it in 2003 - and it's beautiful! After I learned about the diamond trade, I swore I'd never wear one and asked my then BF to get a moissanite ring instead of a diamond (when we started talking marriage).
I have a 1.5 c rock - and it's stunning. I get compliments on it all the time. And a fraction of the price of diamonds. Without the conflict...Another thing to think about!
Good luck, whatever your choice!