Bleh. As (sort of) a fan, I'm not a fan. I much prefer dark arenas in basketball and hockey, so that all the attention is on the field of play. You don't leave the house lights on at movies, plays, the opera, what have you, so I see no reason to do so at sporting events, unless you're doing a whiteout or something. The Blackhawks keep the United Center house lights dim to off, but have the ribbon boards and those dopey "Madhouse on Madison" signs on, which looks a little eerie.