2 and 3. 3 is striking and seems most you, but it has the least agate-y goodness. 2 is an interesting mix of materials and colors. 4 is pretty but the colors don't wow me. I would have to see 1 on a real neck.
Thanks ladies for all your help! I ended up getting the first one, although I really wanted the third one too. Unfortunately I only added the first one to my cart and didn't realize the sale ended at midnight. Weirdly though, the necklace was still in my cart, so I was able to purchase it today, but not the other one. Oh well, I guess it wasn't meant to be mine. Thanks again!
__________________
Fashion your life as a garland of beautiful deeds. -Buddha