Hard for me to say, since I took a break from watching much NBA basketball a few months ago, and am not very on top of other teams' rosters right now. But someone like Joakim Noah would have been about perfect from my perspective. Not saying that we could have gotten him specifically, but anyone 25 or younger, who can actually play C and defend okay would have met with my approval. Some young players who are still projects might have, too.
I happen to find Joakim Noah to be one of the most loathsome players in the NBA, but I know a lot of people would like to have him on this team. I'll give you that one.
But as for the "anyone 25 or younger..." thing, there aren't a lot of players out there like that. That's part of the reason we don't have one. I happen to like Carl Landry, although he's not anything special as far as building a team from the ground up is concerned. But this move was primarily designed for cap relief so that the Kings can be players in free agency and the trade market this summer, and if a big name player is available, we'll be able to make a play on him without concern for the salary cap and matching contracts and such because we'll be significantly under the cap for the first time in a while. It's a move that will hopefully make it easier for the team to be improved before next season.
That said, I think the team is better already. I don't think that Carl Landry is better than Kevin Martin (although I think a lot of teams would do a straight swap, given the salaries and impact), but I do think that he addresses a need on our team, and within a few weeks, I think we can be back to playing the way we were earlier in the season when we were actually above .500 for a few days.
There might be dream scenarios that we can play through in our heads for how this trade could have been better, but given who was available and what we wanted to do, I think we did okay. As of today, I'm giving the trade a C+, and if we improve because of the cap space this summer, it'll probably move up a full grade.