I didn't buy an oil filter wrench since people said it wasn't needed, but sure enough, because the dealer did the last change, the filter wouldn't budge. Not only that, they put some ridiculous torque on the drain plug.

Anyway, a 12" set of Channellocks easily got the filter off. Interesting that the mating surface for the filter on the block is significantly bigger than the OEM filter diameter. At some point this filter must have shrunk...

 

Another tool that works well are mechanic's gloves. I use to use special oil filter grip tools, but a good pair of mechanic's gloves can get it off much easier.