Ok, so, I have to go do something, so I'm gonna have to be brief, I can give more details later. Basically, my Wii runs other games fine, but most times Brawl keeps saying it can't read the disk when it gets to the character select screen after I choose my character. If that doesn't do it in, the stage select screen does. This has only started happening for like a month.
that's most likely you're lens that is broken, many people, including me, had problems with brawl, you either have to send it to nintendo to get a new lens/wii, or you have to use a usbloader (Idon't know, maybe you could also buy a new drive, and just replace it by yourself)
but it could also be your disc