I like yellow brick road for fat quarters that 'go together' theme/color-wise- nothing fancy but I like how you cut then sew certain pieces and shuffle around..just enough to keep my mind engaged. Think it's from Atkinson Designs...now back to reading all the responses and take down notes for other ideas...;-)
there's also another booklet I think from Atkinson Designs that uses half yards and seems like fat quarters are an option - seems like it's called Allegro- I LOVE those quilts and made one almost identical to rhythm and blues and kept meaning to make some of the others just never got around to it.