Definitely the Nets. They have 3 all star level guys on that team, in addition to some solid role players and good young players. It boggles my mind that they're as bad as they are. Makes me really question Lawrence Frank as a head coach.
All that said as currently constituted I don't see this team being better then a 45 win team. This team is terrible offensively. Jefferson can't consistently score in the half court, Vince Carter, unless as rumored, is being a dog again, looks old, Kidd can't shoot it in the ocean and their bigs have no post up games and have trouble finishing. Besides a post scorer, the biggest problem the nets have had ever since Kittles and Harris have been gone, is outside shooting. In my opinion Rod Thorn in the past few seasons has gone from being one of the best gm's to being one of the most overrated gm's.
If the Nets are keeping their 'big three' they should trade Sean Williams for a guy that could score because by the time Williams develops, if he develops, Carter and Kidd will be even worse then they are now. If I was Thorn I'd first call Memphis to see if they could use Sean Williams in a package for either Mike Miller (perfect guy to play with Kidd) or Pau Gasol. If he was really slick he'd propose a package based around Sean Williams and Richard Jefferson to get both Miller and Gasol. Or I'd call Chicago and see if I could get Nocioni and Gordon and if that doesn't work I'd try to get Bibby and/or Artest from the Kings. It'll never happen but Eddy Curry and Jamal Crawford would really help them as well.
The Nets if Rod Thorn makes the necessary moves can be really good and a real threat to win the east.
On the other hand the Knicks have talent, but none of the parts fit.