I wash almost everything, mostly because I hate the formaldehyde they use to keep the cotton from attracting bugs or wearing out in storage before it is sold. That said, if the pattern I am making has a lot of intricate pieces, I may skip the wash since the starch I use isn't as strong as that fabric finish they use on the new fabric.
I like the crinkle effect as well, so I don't mind any shrinkage in the washing machine afterwards. All of my quilts are made to be washable and to wear well.
Pretty much the wash/ not to wash question is a matter of preference.