Cousins for sure, but I see two problems with that:
1) I think the Kings will get much better when he returns
2) He seems to be loyal to a fault
Nerlens Noel could be a possibility - he's already been around two wooden spoon 76ers teams, and he seems to be a pretty competitive guy. I'm honestly not too sure how long he will be able to stand for the constant losing. My guess is he'll probably stick around this year, but if next year starts just as badly he'll probably want out. Who knows though - he might even get fed up midway through this season and try to force a trade.
Gasol, Conley and Randolph might be options if the Grizzlies continue to struggle. The are 3-5 right now with the fourth worst win differential in the NBA.
Theddeus Young wouldn't be a bad piece for us, if the Nets decide to blow it up. He's not a star but he would be a huge upgrade for us at the SF spot, and would improve our starting unit dramatically.
Al Jefferson maybe, if you really want to go there. Not sure I do (with our existing defensive woes up front) but might be an option.
Unfortunately I don't see any huge name stars who look likely to want out. Maybe Carmelo if the Knicks drop off hard (i suspect they will) or Dwight Howard if the Rockets fall apart and prove to not be as good as suspected - but that's a bit gamble with his health and attitude concerns.
Noah is an obvious one, since he's only getting 17 minutes a game in Chicago and may well get frustrated with his role in time. I wouldn't be opposed to going after him, but I wouldn't want to overpay He has declined in a huge way...but he'd still be a big upgrade as a rim protector.