I love the archfey patron because I love that fey flavour, but I also love the hexblade. I think in terms of writing it would also be relatively easy to handle because the breadth of possible patrons is relatively light. They're all basically dark spirits from the Shadowfel (which seems to relate to the shadowcursed lands for extra story relevance) and may be related to the raven Queen. So less variety out of the box on the patron front, as it were.
