History Never Repeats: ads/PSAs for the Spanish Flu (they mention wearing a mask, etc), or any other situation where history has repeated and it's depicted in ads or PSAs. History Never Repeats is also a great Split Enz song :)
Diet drinks and diet foods: it's that time of year where many start diets or exercise regimes because it's the 'new year'. Every day is the start of a 'new year' if you really think about it; but I thinker too much.
Exercise related ads: cuz just like diet drinks and diet foods. Now I have Olivia Newton John's "Let's Get Physical" stuck in my head. HALP!