Steak 44, City Hall, and Donovan's are the best steak places.
I've heard good things about Buck & Rider for seafood. The Henry is packed for breakfast especially. Matt's Big Breakfast is great breakfast.
FNB is good. Roaring Fork. Citizen Public House. Cowboy Ciao. Franco's Italian. Marcellino. The Mission. Etc. Etc. Etc.
Most Sam Fox restaurants are also very well executed and have great food (aforementioned Culinary Dropout, The Henry, Olive & Ivy, etc., etc.). I'm hearing amazing things about his newest place called Doughbird.
For lunch, DeFalco's is great. The Stand has a great burger and amazing milkshakes.
Most of the suggestions in this thread have been good.
But if you're asking me, Steak 44 (technically Phoenix) and City Hall are the best but they're expensive. They have a more upbeat atmosphere. Donovan's is also very good and has a more subdued, classic mahogany motif.
Let us know what you choose.