best purchase has been all my SU stuff. NOthing beats it.
I do say I love my cirlce and oval cutters (with blades and mat) I have from CM (before I found SU!) They are so nice and smooth.
Worst has been the nasty white paper form Michaels. I got it in a pinch to get some baby shower invites out, cause the shower date changed.
I hated the quality. Luckily no one else noticed.
I let my 5 yr old stamp his little heart out on it. He loves my pattern *edging* scissors that I never use, and he just cuts up like 15 pages at a time. With such crappy paper I dont even try to stop him.