Jones is a great fighter. GSP is a great fighter. They're not the p4p kings. Aldo has been for a while in my opinion. I started to rank him higher than Anderson even before Anderson lost to Weidman. Aldo has a very comparable track record and title defenses, has beaten elite level fighters who dropped down a weight class (which none of the other guys have done), and unlike all of those guys, Aldo has the least amount of holes in his actual skillset. His striking, wrestling and BJJ are all great. His only knock has been cardio yet guys still pressuring him to 5 rounds ended up losing convincingly.
If every fighter was the same weight, I would easily put my money on Aldo to be the reigning champion.