Sam Bowie is one of my all-time favorite UK players. Melvin Turpin was a high school friend and teammate of mine, and a classmate of mine at UK for three years -- so my opinion of him goes without saying.
Having said that, neither had anywhere close to the complete skill set Anthony Davis has. Before his injuries, Bowie and Ralph Sampson were ushering in an entirely new era of big men. Their combination of length and athleticism was something we hadn't really seen much of before (other than Wilt). If not for the injuries, Bowie may have become one of the greatest big men ever, but his numerous leg problems curtailed that career. He was never the same after the first one. Turpin was good around the basket, and even had a good shot out to 15 or 16 feet. But that was pretty much the extent of his game, and he never could stay in shape after he reached the NBA.
Davis is on another level. He needs to put on some weight, which he will do, but otherwise his game is perfectly suited for the NBA. As great as he was as a college freshman, he was just scratching the surface of his potential. It might not happen immediately, but he will become a star in the NBA. The fact that he's also a fantastic person is just icing on the cake. Probably the most humble great Wildcat player I've seen. Also had a 3.7 GPA his last semester at UK. He's the complete package, no doubt.