a herringbone pattern would look nice. Your countertop doesn't appear to be too busy so it would definitely work. I would extend out to the end of the counter. there's no right or wrong answer to that, but looking at the photo, that would be my recommendation.

I would not go with a herringbone. It will be hard to end it and have it look right since the pattern is so complex & your cabinets don't end directly above the countertop. I would go with my old standby, subway in a running bond horizontal pattern. Off- white porcelain. And I would carry it up from the length of the countertop to the ceiling on both sides & around the window. Those tiles are inexpensive enough to do that. Good luck.