12th Avenue Grill    In the nearly five years of its existence, we've never had a bad meal at 12th Ave. Grill, where Kevin Hanney, a caterer turned restaurateur, takes a fresh, unfussy approach to American standards. His signatures are a to-die-for mac and cheese (sooo rich) and a slightly spicy kim chee marinated steak, but do check out the specials above the red oak counter; we've always found something interesting there. The like-mom-used-to-makebut better desserts run to seasonal fruit crisps. Our only complaint is that, when the wood banquettes around the walls and the tables in the center fill up, the noise level soars, so we tend to go early. Full bar and wine list. (And try a tub of Hanney's amazing smoked 'ahi spread for noshing at home.)  1145C 12th Ave. 732-9469., 5:30-9 p.m. Mondays-Thursdays, 5:30-10 p.m. Fridays-Saturdays. Reservations recommended. JCB, MC, VS. No checks. $$$.  Web site: www.12thavegrill.com