When I watched VH1’s “Top 100 Greatest Songs of ’00” yesterday, I was reminded of how hot & sexy Christina Aguilera USED to be– but lately, all we’ve been seeing is the singer on a downward spiral– mentally, physically, and now fashionably. At tonight’s Michael Jackson Forever tribute overseas, Aguilera re-defined the term “hot mess.” Hit the jump to see the pics… Wendy L.