We don't go out as often to Gaslamp so I may not be up on the totally hip & current. That said, here are some favorites:
Blue Point - seafood & steaks, consistently good. A Cohen restaurant - they know what they are doing.
Candelas - Mexican seafood, but more Mexico City / Spanish than the Mexican you are likely to think of. We LOVE this place. A little out of the box of basic seafood/steaks which makes it fun. The Sea Bass is to die for. It also has a hip, cozy bar that gets going later.
Fish Market - A handful of blocks from the Gaslamp, but if you want a view the bay and are a little more seafood oriented, try Fish Market. Casual downstairs, upscale upstairs.
Searsucker - Heard good things but haven't been yet.
Urban Bar & Grill - Also heard good things but haven't been yet.
Other steak places which we have not been in a bunch of years but carry good reviews:
George's on 5th: http://georgesonfifth.com/
Did the Strip Club - didn't like it. OK food, but for that kind of price I don't want to cook it myself.