Shake Shack. In addition to their standard vanilla, they have a special flavor of the day—a weekly schedule which changes each month. I can't tell you how delighted I was to find that basil made a comeback as August's Thursday flavor. My coworkers can attest, as they all heard my loud gasp of joy upon checking this month's schedule. They can also tell you that I haven't stopped talking about this basil frozen custard since the last time Shake Shack offered it... which was 2 years ago.
Time to clean out the freezer... I have a feeling it's going to get filled with pint containers :-)