If you're looking for a thrifty option, your best bet is these Charles by Charles David Mules. It's a wonderful item, while not very pricey. Another strong contender for your wardrobe is these Isola Mules. While the price of this product is competitive, it will surely attract a lot of attention. You may also want to look at these Sofft Mules. This item is not expensive either, but it will make a difference in your wardrobe.
If you want to splurge, then what you're looking for is these Balenciaga Mules. It's more expensive but worth your money. While you're at it, also have a look at these Gucci Mules. Yes, this item is expensive, but it does not mean it's not worth it. And how about the luxurious Valentino Mules? Yolo, right?