Okay, I voted for WDW and although I have never been to Disneyland I plan to one day. For me, being in the middle of the US, I have never ventured West even though it is about the same distance to both WDW and DL. Not sure why, but I guess I look at the total experience. WDW seems to have so much more to offer, that I choose to go there and Epcot is the best park ever created by Disney, in my opinion.
As far as the amount to do, we are going this wek for our 8th trip and I am still finding "new" things to do that we haven't done yet. Yes there are the rides that are our favorites and shows that we enjoy, but it still seems like a different trip each time even though it is the same vacation destination.