Right now, pinwheels are the bane of my existence. No matter what I try, three of the points match perfectly but that fourth point is always off. I know I shouldn't be so picky when it comes to that, but it doesn't make sense to me that three out of four are absolutely perfect but that fourth one is always off.
Favorite though is the nine-patch, can't get enough of them and I can whiz-bang a quilt out in no time doing them. Second favorite is the Double Wedding Ring, I had such a blast doing it and it was so easy that it almost became meditative. I could get lost for hours in that quilt and I do plan on making several more.