One of the biggest dominoes in 2010 FA is Chris Bosh, not just due to his own ability, but in how he lands could effect where LeBron James lands. It could also be argued that where LeBron lands effects where Bosh lands depending on whether you are a chicken or egg guy.
That being said, as of what we know now, Toronto has some power over his destination. They have a list of teams to work with. Now it could be that the list will be narrowed down as FA approaches. Bosh may have given them the list simply so they can start figuring out what packages of players to look for and do some scouting in advance, but may narrow down his choices at some other point.
Or, the possibility exists that he's giving Toronto some control over his destination in order to get that 6th year. So with the possibility of the latter here, let's play a game of "What's your best offer!".
So let's look at the assets these teams have for a sign and trade:
The New York Knicks:
Danilo Galinari, Wilson Chandler, Toney Douglas, Eddy Curry, a 2013 1st, 2015 1st
On first glance, you're thinking what? Eddy Curry an asset? He is if you take back Hedo Turkoglu's nasty contract as part of the trade. Toronto would probably love the do-over on that one.
New York needs to be careful though. Even if they land Bosh, it's going to be tough to land LeBron if they trade all of that, and the team is literally Turkoglu, Bosh, LeBron, with their next 1st rounder coming in 2014 and having to add 9 guys at the veteran minimum.
I doubt LeBron or Bosh want to sign up for that. From a reasonable perspective, I think they'd be willing to part with Curry and take on Turkoglu (this doesn't hurt them at all really), and maybe offer up a future pick + Chandler, Douglas or Galinari.
They're in a tough bind, because if it comes down to a bidding war, they can't really afford to give up much talent. Even with LeBron and Bosh, if they have no one else at all, the Knicks will have a hard time of it. Turkoglu for Curry is probably their most attractive piece in the trade. I'm not sure if they offer out Galinari if Bosh/LeBron would still be willing to go to a roster that empty.
The Miami Heat:
Mario Chalmers, Michael Beasley, and a truck load of 1sts (2010, 2011, 2013, 2015 + Toronto 1st (lotto protected through 2014))
The Raptors reportedly don't want Beasley, and his value has been very low. Rumor has it that he was only fetching expiring contracts at the trade deadline last year. His salary actually isn't that low because he was picked so high. He may not really even be worth his contract.
Chalmers is an okay player, but he clearly doesn't have much ceiling to his game and is probably no more than a 7th man. You'd take him back and be happy to have him as a throw in, but he's hardly a centerpiece. The Raps could get their own draft pick back which would be nice, and maybe Miami sells the farm on it's own draft picks, but they'd better hope Beasley pans out then.
The Chicago Bulls
Joakim Noah, Taj Gibson, James Johnson, and a truck load of 1sts (2010, 2011, 2013, 2015, chralotte 1st), and certainly Hinrich/Deng though it's a stretch to call them assets.
The Bulls have reportedly made Noah off limits in any kind of trade, and I don't blame them for saying that. Now if push comes to shove, and LeBron is coming here if we get Bosh, and we're holding Noah back from getting Bosh then I think that restriction goes away.
That being said, the Bulls could reasonably offer up Gibson, Johnson, and the Charlotte pick (which has the highest probability of being valuable of any pick Toronto could get back from any of the contenders here) as well as a couple of their own picks.
From the Bulls perspective, the primary problem is that if they want to lure James, they need to send Hinrich or Deng somewhere as part of the trade. That probably adds negative value for Toronto, so they then need to overcompensate with something else, or send something extra to another team to compensate for being the third team helping out.
Hinrich + Johnson + Gibson + charlotte 1st + whomever they take in the 2010 draft is probably around what you'd expect to go out int his type of scenario though whether all those pieces go to Toronto is up for debate.
The LA Lakers
Andrew Bynum, and some 1sts (2011, 2013, 2015)
Bynum's game fits perfectly with Bargnani if he's healthy and proves that he's good and not just good because he's playing with two super elite offensive players. However, that's a lot of ifs for Toronto to take on, and his contract isn't exactly a special bargain either as he's compensated quite well.
He's the best player when healthy and also the best fit, so he'd carry a lot of value. the Lakers picks probably add very little value to the equation here because they're a lock to be one of the top 3 teams in the league.
So who can make the best offer if Toronto really has a say?
It depends on what they want:
LA offers the most talent, but the worst financials.
NY offers the least talent, but the best financials.
Chicago's offer depends so much on whether they try to force Toronto to take Hinrich/Deng or find a third team.
Miami's offer is basically crap unless Toronto likes Beasley which rumors say they do not.