Best Moderately Priced Restaurant Near GRB

We've got a group of 30ish that are looking for a restaurant near the GRB/Discovery Green (within a few blocks; walking distance) for dinner in a few months. The group will be people who are from out of state and I want to show of the best of Houston. The group would also require a private room.

While being from the area, I never spent time downtown and not since it's undergone it's revitalization. I saw there's a Pappasitos, but I've never been super impressed and thought there was better texmex. I love me some Saltgrass as well, but there are better steaks and it's not very unique to Houston.

Finally, the pricing needs to be "reasonable". Like less than $40 a plate, preferably nearer to $20-30.