Located in the formerly improbable (but more recently, less so) neighborhood of Wallingford, the Sea Monster Lounge actually manages to be dark, a little sexy, and smoke free -- a rarity in Seattle, and probably an impossibility downtown.
Live music nights can be a bit loud, but that's not every night. There are little semi-private side rooms towards the back that seem like ideal makeout spots, if you're on a date and its going well (or you're out for a "date night" with your partner, which always go well). Drinks are reasonably priced. And it doesn't feel like a "fake bar" like the myriad ale houses around town, Tangletown, Hales Brewery, etc where beers are served but there are more young families than hipsters and single-types. (Not that there's anything wrong with those places - as a married, employed, kid-having guy, I spend plenty of time in those places, too.)
One of the only "real bars" in town where you don't have to Fabreeze and shower when you get home if you like your booze without a carcinogen chaser.