Halo,

I think the best way is to do it, is with Ethernet: use a CP243-1 in S7-200 and a PC with Ethernet Card (WinCC 6.0 has already the driver) and a cross over Ethernet cable.

A alternative, if you want to economize the CP243-1, you can use, for example, MPI: in this case you must use a integrate interface of the PLC, but than you must buy a interface for the PC (for example CP5611), and the performance will be worst.