What makes a good sandwich?

I am starting a new and hugely exciting project involving sandwiches. That's all I can say for the time being. But, you, my wonderful readers, can help! I've created a poll designed to find out what you think is important when it comes to judging the quality of a sandwich. If the answer isn't on the poll please leave a comment. And if you have any thoughts that can't be captured in the poll leave a comment too.

Here's the poll:

I will keep you all informed as this develops. Ultimately we need to develop a method of judging the quality of a sandwich in a repeatable way.

Please help!