Ornery, I prefer a hub/switch because of expandability. thebestmax never said how many pc's he had. If it's more than two, or if he has any expectations of more than two, then direct connect is out of the picture. It's always nice to know that you have an open port in case you need it. It's also nice to have if broadband internet access is in the future.
I also like the flexability of a hub. Instead of running one long ass cable, I can run two shorter cables. It makes it nicer if I ever have to move on of the pc's to a location farther than it was originally. Also, from a connectivity standpoint, the visual feedback of a hub is nice. If I've got PC's in four different rooms, and the hub is by my main PC, I can tell by the status lights of the hub what PC's are powered up, and whether or not they have a connection. It's just for a visual troubleshooter.
I'm talking out of my ass on this one, but I also believe that hubs/switches offer better transfer rates than a direct connection. I've just used them in the past, and transfers seemed to take longer than if I had been using a hub.