My Take
Ok first off I'm very aware that Ozzy is one messed up individual, no one needs to tell me this. Honestly I probably new it long before the Ozborns ever hit the air waves. I had read enough on the guy and seen enough videos of him that I new shit wasn't right in his head, I will admit I had no idea that it was that messed up. With that out of the way and regardless of how screwed up he is, he's probably my all time favorite artist, thought the Counting Crows are moving in on that position, something I'm sure there excited about. Ozzy has never released an album I didn't like, I have been waiting for one to suck but he knows how to surround himself with talented people, this isn't hard for him since a lot of mettle heads consider him to be the shit and volunteer to work with him. His musical image is just that, an image, and he works it well, but there is far more to him than his son of satan gimic. If you listen to his music you can hear the ranttings of a very confused individual who also has one of the best grasps on reality I have ever herd. Either way he's fealling it's his lot and he seems to handle it, not always well, but he handles it.
A list of my favorite songs by him would be too damn long, the main one's are Killer of Giants, Road to No Were, Crazy Babies, Crazy Train, Over the Mountain, and the list goes on, damn got to mention Ultimate Sin. I love the songs for various reasons, I can relate to some, others just rock and make no sense, the song Ultimate Sin said something I never could. Another thing that attracts me to his music are the guitarists he has had Play for him. Randy Rhodes, Jake E Lee, and Zack Wild. These guys all kick ass in there own right. Randy was by far the most techinquely talanted, Jake the most creative, and Zack the best soloer of the group. If you toss in Tonny Iommy from Ozzys Black Sabbath days that would make four of the best ever.
Ozzy and Zack 
Ozzy and Randy
Ozzy and Jake