There are plenty of fine spots in the Eastside. You sound like you live really close to where I live in Kirkland, and I rather enjoy it as well. I have a little walkable town with swimming access in the summer, a fast bus commute to work in Redmond, convenient highway access to summer parks / hiking, and a direct bus to the city for weekends. Works great for a family like mine where we like to hit the city in the winter and then play in the mountains in the summer and we don't eat out a ton. Most of the year I do a 6 mile trail run for my morning commute and I wouldn't trade that for pretty much anything.
However I can totally see where much of the Eastside gets a bad rap. For starters, as already mentioned if you are looking to go out every night, then there are much better places to be. And (this is the big thing that I see) if you get even a little bit too far North, South, or East you can very easily get into a position where it takes you 45 min+ in traffic or multiple bus transfers to get anywhere interesting. Folks come in to work at Microsoft, think that they need / want a big house and end up way out in a place with no easy access to get anywhere and annoying traffic. Obviously this still works out ok for some people, but it's the big frustration that I see from lots of Eastsiders.
To get off of the Eastside...blah, blah, blah talk. Anyone else a trail runner in the Seattle area? I'm starting to get all my races lined up for the summer. Currently aiming for Rattlesnake Ridge 50K in June as a lead up to the White River 50M in July.
I'd done races with both Northwest trail runs and Evergreen trail runs before and they were all really well done races. Lots of them have short running options and the events are all really friendly and almost all in beautiful locations. My only warning is that once you start doing these you might get pretty spoiled for traditional road races. I've been running marathon+ distances on the trails, but I'll probably never do something like the Seattle Marathon because I have no intention of running 26 miles in the middle of a huge crowd on concrete. Just had to put a plug out there are the start of the season.
http://nwtrailruns.com/
http://evergreentrailruns.com/