1.2 What-if? (?)
2.1 Fantasy Fulfillment
2.2 Escapism
2.5 Sense of senseless violence (working your aggression out)
2.6 Opportunity to do those things we normally only get to read about.
4.1 Between characters involved in interesting relationships, events, etc.
4.2 Between a number of players sitting around a table laughing
5.1 Unless, of course, you bought the ADND Monster Compendium!
6.1 Solving puzzles,
6.2 See also Battlefield tactics
7.0 Getting an Educational experience
7.1 Great way to learn about psuedo-midaeval European history