Joe C.
Yelp
Vania K has it exactly right; this is primarily the "Museum of Seattle's Awesomeness." I was hesitant to spend precious vacation time at the Museum of History and Industry* because my history museum standards are pretty darn high and I didn't necessarily want to visit a general history museum. But thankfully we were guided by a friendly employee directly to the second floor, where we learned that it's very much a "the history of Seattle is really cool" museum. I loved the intro video, particularly the clip where Bill O'Reilly says Seattle has now become a beacon of secularism as terrible as San Francisco ... since apparently the curators see it as a compliment. How nice that Bill and the residents of such a liberal place can agree about something.
We thought we'd spend an hour or two on the "history of Seattle" section, but it wound up being over three hours just on that second floor working around the gallery. The story of Seattle told here is truly impressive, with frank treatment of the bad and unabashed cheerleading for the good. I never understood the paranoia over admitting that nations, states, towns and citizens have done bad things in the past, and it was refreshing to see that honesty and a relatively evenhanded treatment of controversial topics. There are several interactive displays, which I'm not ashamed to say I spent a good deal of time fooling around with ... I enjoyed the neighborhood recommendation engine in particular, though apparently my wife and I will have to compromise quite a bit if we move up here and decide to live in the same house.
The rest of the museum contains some nautical history, plus a variety of rotating exhibits (an homage to chocolate was there during our visit, worth it just to go in the doors and get a whiff of that cacao smell). Also worth your time but not necessarily as extensive as the core Seattle history section. Figure 4-6 hours overall, half that if you're a fast browser.
Not much to the first floor. The "Bezos Center for Innovation" is a revolting abomination, a paean to the unreflective lucky^ and an embarassment to the rest of the museum. I love Amazon and have nothing against the company, but the cartoonish philosophy espoused in that area is truly disturbing.
It's very much worth your time to enjoy the lakeshore near the museum as well, since you can see Kenmore Air taking off and landing their float planes. Validated parking is available on the west side of the lake.
* "So THAT's why they call it MOHAI," I thought to myself a disturbingly long time after I first heard the term.
^ My point being that success = hard work + luck, in contrast to those who seem to think s = f(hw). Oh, and s does not equal $ (once $ reaches some arguable minimum threshold; I'm not going to let this note devolve into a Maslowian discussion).