I love all aspects. Except when things aren't going well, then whatever the problem whether choosing fabrics, designing, piecing, quilting on my domestic machine-- that part gets momentarily demoted to not love until the problem is solved.
If I had to choose my least favorite aspect of quilting it would be precision piecing, or doing any part that requires putting lots of the same units together-- which is why I do so many art/improv. quilts.
I like to doodle quilt for relaxation.
I even enjoy the sandwiching and basting part...
Rob