TF2 seems more fun because battles are longer. Imagine TF2 with one hitpoint. Whenever anyone hits you, you die. Does not provide very interesting battles, and most people are dead most of the time. In DoD, you seem to die too quickly. One of the key points in TF2's design is that running around shooting bullets is the most boring game you can have. That's why a huge emphasis was placed on melee weapons, and "special" weapons like the Engy's turrets, the Medic's heal gun, the Pyro's flamethrower, and the Spy's backstabbing and sapping ability. Everything seems to be countered by something else, so certain classes are overpowered at certain points, and underpowered at others. And TF2 is just so... funny. The character's personalities are so distinct that, for example, the Spy, the dignified european says, "I appear to have burst into flames." Well, DoD seems bloody in a depressing way, TF2 seems bloody in a really funny way.