I'm biased cos I read the slush there but Ray Gun Revival tries to recapture the spirit of the golden age SF over at:
http://www.raygunrevival.com/
They publish one new story a week and there are a couple of on-going books being serialized.
This was a recent-ish anomaly. Normally it's a fairly PG-13 site but this is noir SF with an edge you normally see in the crime pulps:
http://www.raygunrevival.com/the-kin...n-andy-henion/
Mike Resnick is published there quite regularly:
http://www.raygunrevival.com/tag/mike-resnick/
While not exactly the polar opposite of Clarke's World (which I greatly admire) we generally publish a "type" of story which tends more to action than some of the more intellectual stories you'd find in CW.
SF is a 100 genres within a genre (with a fractional readership as is) so you'd need to let us know what you like before we can direct you.