Depending on what happens with trades, my top 3 are Aldridge, Rodney Carney and, based on what I've heard, Tyrus Thomas (haven't seen him play). The Kings need athleticism, and these guys have it.
I agree with Brick, I don't think Shelden Williams' game will translate to the NBA. He's undersized, he's not that athletic, he struggles on man to man defense and has given up career games to good power forwards.
P.S. If the Kings have a pick around 13-14, I'm all for Matt Haryasz. He's athletic, good rebounding skills, good on offense inside and out. He'd be a good fit for the Kings.
Here's his last six games, against some very good Pac-10 teams:
Cal: 24/10
Arizona: 25/7
ASU: 27/10
WSU: 22/9
UW: 24/10
Oregon: 24/14