I am going to go with Barkley, but Malone is not too far behind, in my opinion. Webber was a good player, but he did not have the nastiness that the other two exhibited. Nobody was ever afraid of C-Webb, but plenty of players were terrified of Barkley and Malone.
I would have liked to see Malone play without Stockton in his prime (Lakers years don't count) and see if he did just as well. I am a big Stockton/ Malone fan, but I am never sure if one made the other or if they were both just that good.
On the plus side for Malone, if I remember correctly, he was probably the most durable big man since I remember following basketball (Granted, that's not all that long.)
Again, I'd take Barkley, but in my opinion Malone is probably just as good. I am probably voting for Barkley because I am a homer. If two players are pretty much equal, I think it's fine to be a homer and pick the one from your team.