According to the NKBA 70% of time spent in a kitchen is at the sink. Think about it. Therefore, the location of the sink is REALLY important. If you are the type that likes to socialize with family members or guests, or your kitchen opens up to a great room full of activity - the center island or peninsula is a great place to locate your main sink. I often refer to this location as the helm or command center. The person at the sink stays visually and conversationally connected.
If you are lucky enough to have amazing views, you may want to locate your main sink under a large bank of windows. Beware the exposure of the window if this is your choice. A sink on a western exposure wall will leave you hot and blind - or force you to cover your view which totally defeats the purpose.