well, people hate sawyer, because he's the packrat... but while everyone was freaking out and running around, he collected EVERYTHING he could get his hands on. he's looking out for number one. that's your survival right there. now, he's still being social, and hasn't murdered anyone. however, he's been attacked a few times. tortured eh? and more. he still hasn't really cut out on anybody. chances are, he's going to come out ahead, until he's forced to make a selfless act. i betcha. now, people are hating him for looking out for number one.
enourmous guy - he's got some interesting karma. his new gf is going to be ... interesting too. trust issues. i bet he saves their bacon. with fava beans

just kidding. he seems like a good guy. pregnant chick? who knows. she's hot, might pull her own weight. the baby is probably a "key" for later. who knows.
anna lucia? yeah, with sayid, she'd have had an accident, secretly, made to look like the "others" did it. also sayid, with his training, he probably should've would've taken sawyer's good stuff, a couple bags, and bugged out and watched in secret, from afar, kinda like "the french chick" danielle.
lock? he has his agenda, no idea what. he doesn't need anyone, but why is he hanging around now? especially preggers chick? mmm.
a lot of the others... hard to say.
i don't think the loneliness factor would enter into it for years and years. it's not like the island is truly empty.
bladite