If you're budget-restricted, your best bet is this Montblanc Pendant. It's a wonderful item, while not very pricey. Another strong contender for your wardrobe is this Kenzo Pendant. While the price of this piece is not very high, it will definitely attract a lot of attention.
For something in the middle of the price range, you're in luck with this Maison Margiela Pendant in stock and waiting for you. You are guaranteed to fall in love with this product. Why not also consider this Valentino Pendant. It's an attractive option both price and quality-wise.