Haven't had Pizza Shack in Jackson have heard good things about it. Roma's is only one in North Jackson area with a real Brick Oven that I know of. The brick oven makes a difference.
The people who answer Mellow Mushroom, get real... Just tell everyone your favorite burger is from Chili's, your favorite steak is Outback, your favorite taco is Taco Bell, your favorite Po-Boy is Subway, etc... Mellow Mushroom is crap.
Soulshine is also good to me. Its probably 2nd in my book. Like I said I haven't tried Pizza Shack going to soon though.