I don't know about Fructose vs. Corn Syrup. Both are very bad Sugars IMHO. Now, if you were comparing Lactose to Sucrose or Corn Syrup, I would definitely say Lactose is the better choice. Here's the order [from most evil to least evil] of how I view sugars:

1) Maltodextrin
2) Dextrose
3) Grain [Corn, Brown Rice, etc...] Syrups
4) High-Fructose [HFCS, Honey, etc...] Syrups and Powdered Fructose
5) Sucrose
6) Lactose
7) Tagatose