All of them. Duh.
Story time: Summer after ninth grade, must have been 1992 , two friends and I saw him at the Arena Theater (dumpy little theater in the round in Sharpstown) in Houston. We were pretty close to the stage, as it turns out. After "Smells like Nirvana," he smashed his guitar and pieces went flying. A roadie picked some pieces up and ran over to us and gave them to us. We thought that was the highlight of the night. After the show, we were standing outside waiting for our ride, and noticed his tour bus right there. We went up to the security guard standing by the back door, showed her the guitar pieces, and asked her if she knew when he would come out so we could try to get them autographed. She told us to wait a minute, went inside, came back outside, and said, "Okay, he's right in there. Just walk through the curtain." So she let us in, we walked through the curtain, and sure enough, Weird Al walked right in, on his way out. We showed him the guitar pieces, he happily signed them, shook our hands and said "Nice to meet you." It wasn't until we were all outside, giddy as, well, a bunch of Weird Al nerds who just met Weird Al, that we realized we should have done the "we're not worthy" bit from Wayne's World. Anyway, I still have that autographed guitar piece, on a shelf of honor in my fun room. My wife hates it. (One of those same friends and I saw Weird Al at the Wortham Center in Houston a few years ago. We got there late, as he was doing his first song outside the entrance to the theater, and he walked right past us on his way in. Also pretty cool.)