Green Lake is a very desirable and busy Seattle destination. My neighbor growing up was from Ballard, and said that back in the 30's, Green Lake would freeze over every winter, and they could ice skate. Nowadays it's perpetually liquid and honestly kind of weirds me out with its murkiness, yet I see people swimming in it all summer. There's a zoo on it; it must be full of flamingo poo. Go run around it or something.
Location: 7201 E Green Lake Dr N, eastern edge of Green Lake.
Number of swings: 6 regular, 2 baby seats, 6 baby buckets
Ground material: Wood chips
Chain length: Long.
Notice that 4 of the regular swings are the regular seat, and 2 of them are hard seats. Variety! And long chains. And lake views. All these things are good things. 6 swings means higher chance of snagging a seat, but this park is quite busy on nice days, so maybe you'll have to wait. Being in one of the most prominent parks in Seattle, these swings set a more-than-acceptable standard.
How to get there: The 48 runs along Green Lake Dr., and the 16 and 316 run along Woodlawn.