We ate at Gruet Steakhouse (of Gruet wine fame) our last visit to Abq and really liked it. It wasn't jeans casual, but neither was it dinner jacket fancy if that helps. The food was excellent. It's on Central, and probably 4 miles or so from the fairgrounds. Atlhough it's a steakhouse, they also had fish and other choices. We had the shrimp appetizer and shared a steak and left happy
There's also a decent Thai place near the fairgrounds, but the name escapes me at the moment...Larry Greenly, who posts frequently on the food forum, would know. If he doesn't see this (don't know how much he checks anything but the food side of the house), drop him a message through this forum.
The Frontier, across from UNM on Central, is a decent greasy-spoon kinda place for breakfast and their cinnamon rolls were good, by the way. You can always look on Chowhound.com for ideas on where to eat, too.