I'm a big fan of the Union Grill. Me and my friends meet for lunch in Oakland once a week, we will try to make it to UG at least once a month. Everything I have tried is good.
Today I had Mahi-Mahi fish taco and it was excellent. UG is known for their burgers, of which i have had several and have all been big and delicious. With their sandwiches they have a variety of sides which is nice. The mashed potatoes are my favorite but today I had a little side salad. Not to shabby.
They usually have a nice beer selection which rotates, and in addition to beer there is a full bar and a cheap wine menu. Their soups and desserts are great. They dessert menu rotates so everything feels fresh and seasonal. This is a great place to meet someone for a business lunch if you are in Oakland, or if you are in college, this is a nice place to take your parents.