Orkut is dead...Facebook killed it. Gone are the days of scraps....It's fb now all over.
I think Google + but it's take some time...not easy to challenge the Facebook popularity.
Honestly think if G+ had a shot at dethroning facebook they'd have made bigger inroads by now. FB isn't unbeatable, but they're well entrenched.
I can't believe Classmates.com hasnt figured out they are dead yet. Who the heck gives them money for services they can get better for free?
-- Do not meddle in the affairs of dragons, for you are crunchy and good with ketchup. --
As far as social media is concerned, Facebook is far ahead at this point in time. But Google has many products not just confined to G +. And that's the biggest advantage. Google + hangout is the best feature of G +.