I have been asked to comment on cardstock.
My white preference is by far, Paper Trey. It dry embosses like no other, is thick enough, and it is very white. I also like it for usig markers and watercolors. It takes ink beautifully too.
For my less expensive white, I do like GP (Walmart) and find it about equal to SU, but much cheaper. I use it for layering and backgrounds mainly.
For colored cardstock I use SU for my basics and Bazille Bling for shine. I also buy Carnival Red by the large package at Paper Zone. I cannot find a true enough red besides that one. SU's Real Red is still just a tad not deep enough for my taste. I like a very deep true red.
I have lots and lots of other stuff I picked up in my early stamping days that I use now and then. SU has never come up with a baby pink or a baby yellow to suit me so I buy from a scrapping store in Issaquah, WA. I also use lots of my older stuff when making things for my students since they have no idea about cardstock quality. I also let them use it to make things, but my GW board friends have donated lots of cardstock so I am well set there.
I use SU's smooth Vanilla since I have not found anything comparable for that. I also tend to use their glossy and their vellum, just because it is convenient to me now that we don't have a lot of choices in the area.
I buy my designer papers at both local stores and Craft Warehouse, as well as probably nearly half of it online from All That Scraps mainly.