hmm...tough choice....I'd say b.zero1 or something from Tiffany's.
The b.zero1 pendant is quite fun and charming, I love the spring action of the piece. I am not really a logo person, but I love the b.zero1 collection (hubby does too and he is an anti-label type guy!), Something about it is quite appealing. And I would definitely get a non-designer chain to go with it as you mentioned in the bulgari thread.
For Tiffany's - do you have any particular pieces in mind? For charms, I love the small Schlumberger eggs! I love a lot of Peretti's designs in gold: I like the Sevilla small pendant, the eternal circle thing (the one that looks like a stylized ouroboros), the apple, and I particularly like the lapis lazuli bean on a gold chain!
The small trinity ring and trinity necklace are nice...but a little underwhelming IMO. And don't you already have a few trinity rings already? I think it would be nice to get something new/different!
VCA sweet is cute, and I think it would look great layered with your other VCA necklace, esp. if you got the Carnelian, but I think I'd still prefer something from Tiffany's or the B.zero1!
I am with you on that. I am considering something in rose gold from Tiffany's or bulgari.