What are the best fancy restaurants in Downtown Houston?

I'll be staying at the Hyatt Regency downtown soon, and I'm trying to find some absolutely incredible, unique, and romantic food places (hopefully within walking distance, but also willing to drive)! I'm not really from the area (lived in San Antonio and DFW most of my life), so I'm a little lost. After some searching, I've got some bars in mind, but a nice dinner is giving me a little trouble.

Does anyone have any good recommendations? Price isn't really an issue, it's a celebratory thing! Even if it's not fancy, I'd love to hear about it for a good lunch/breakfast! Thanks in advance!