I haven't worked downtown in 3 years so not sure what has opened or closed there but Something Italian and South Union was definitely 2 I liked. The Panda Chinese place in the kaleidoscope food court is decent, loved their generals chicken. Fuzzy's Tacos and Guru BBQ is in the same building, may have to drive a few blocks but it is worth it. Centro which is right next to South Union may be one of the best restaurants in town if you want a good sit down meal.
The Local Bites food court, in the basement of the Partnership Building on 7th and Locust, is great. The Mexican place down there is awesome, much much much better than the one in the upstairs food court. Indian place is good, too. Farm Boys and the stand/kiosk in the middle are great, same owners.
JJ Jasmine Thai in the upstairs food court is solid, quick and reasonably priced.
You should be taking advantage of Restaurant Week this week. Try out new stuff and figure out what you like. There are a lot of restaurants downtown, and there's always more opening.
I second Bernardo's. Underrated spot for good, quick Mexican street tacos, burritos, etc.
Lots of good options in this thread so far. I'm usually on the low end price wise when I go out so not as likely to do a Centro etc as I am Fong's, Bernardo's, etc. I do make a point of going to Court Ave Brewing occasionally as I like Scott Carlson and respect what he has helped do for downtown and the Court Ave. district.
I would also recommending hitting up one of the special food truck lunch events they have from time to time. A variety of options, live music, etc. Locations vary but this summer they had one by the sculpture park, one at 8th and Walunt, etc.