Many sports fans keep and collect recordings of their favorite teams' games, because subsequent video releases of those same games often chop it into highlights, remove the original commentary, and add "dramatic" music.
Up until the advent of the NFL Network, classic NFL games were relegated to being shown either as iconic highlight clips or edited NFL Films productions. Even now, the network's classic games reairs haven't gone much past the last ten years.
During the earlier years of ESPN Classic, MLB, NBA, NHL and other leagues would allow some game broadcasts to be re-run on the network, even if they weren't originally carried on ESPN (The NFL never allowed this). It's pretty much been stopped now as the leagues have created their own networks and are hoarding the game broadcasts for use on said networks.
Formula One racing was really bad for this; the DVD review was the only place for highlights, and they were often "enhanced" with fake commentary and music. There was nothing on the official website, and any old races that appeared on YouTube were immediately pulled. In 2009 there's been a minor turnaround, with videos on the web, and the BBC showing classic races on TV and online.