1. "Hear me out..."
    Well now I'm suspicious.
  2. "Listen..."
    I was! In general, people don't respond well to commands.
  3. "I'm not racist, but..."
    Oh man, this is the Stairway to Heaven of qualifiers. A classic that spans both generation and class.
  4. "I'm not trying to be rude..."
    Unless you follow this up directly with "but hey pretty girl I'm feelin' you" then whatever you're about to say is absolutely going to be rude. (Author note: False promising R. Kelly is possibly the rudest thing you can do.)