EMP rocks, but be prepared to spend 2 to 4 hours minimum.
A lot of good places for brews in the area, and we have seen a large growth of beer houses that have a stupid number of taps. I have no idea how they manage to keep their lines clean.
If you are looking for local brew houses, there are some great ones in Seattle, but from downtown you could go to SoDo where there are a handful of nanobreweries going in the industrial district: http://www.seattlemet.com/bars-and-n...sodo-june-2011
Old article, check addresses, but they're still there.
EMP is good. Pioneer square is good if you want history, but otherwise it is filled with bums - has a great tour though. Seattle Center is surrounded by a wasteland, but is otherwise good.
If you are looking for cocktails downtown try Zigzag, they have great bartenders. If you are looking for high-quality fish dinner that will not completely break the bank go to Steelhead Diner (try the crab cakes) in the Pike Place Market. If you want to break the bank (but the lunch menu is reasonable) and eat fresh oysters, give BlueAcre a try. If you want Italian, Pink Door can be fun on the right night of the week (they have trapeze artists sometimes). But one of the best Italian places in town is La Medusa in Columbia City (take the lightrail and walk a few blocks).
SeattleMet just put out a new bar list: http://www.seattlemet.com/bars-and-n...bar-march-2013
Might want to glaze over that one.
If you have time and want to get to know Seattle, pick a few neighborhoods to visit and walk them. The University of Washington is a gorgeous campus and an interesting district; Capitol Hill has some excellent restaurants, parks, and ice cream options (Molly Moons!); Queen Anne is fun, but a bit of a shriveled nipple for content these days; Ballard and Fremont are out of the way, but have a lot of character, nosh, and brew; Columbia City is a small, seductive little micro-townlet within Seattle (there are dozens of others too, but it is fun).
Activities, go right the Seattle Wheel (someone has to take it for a spin), maybe do the museum. If you love cars and don't mind renting a car and driving a bit further go to Tacoma to the LeMay musem http://www.lemaymuseum.org/
(totally worth it), you could couple it with a microbrew tour by hitting up the micros between Seattle and Tacoma and back again - just make sure someone sober has the wheel.
If you want to see a pretty island, check out Bainbridge Island and while there go to Bainbridge Island Brewing: http://www.bainbridgebeer.com/
Von Trappes on Capitol Hill will give you a taste of Germany, sort of, is often crowded, is a bit too hipster-fratboyish at the moment (it will tone down, but it is new), but you can spend some time playing Bocce on the indoor courts so why not.
Want to enjoy some views from the waterfront, take a ferry to Bainbridge, or at least to West Seattle and then walk the waterfront. If you go around to Alki Point you will find dinner at several places, including Duke's (good food, not as good as it was five years ago) or Anthony's (far too expensive).
Quinn's sometimes has some solid microbrews from time to time.
What exactly are you looking for or do you like? I mean there are some amazing experiences in the area, but they can be expensive (like Canlis or Herbfarm) and amazing. Just depends on your time and dedication. And then there are some fun things to do, depending on what you like to do - take a day drive to the peninsula or up into the mountains, or just stay in town.