Vizio SB36514-G6 36" 5.1.4 Channel Home Theater Sound System and Wireless Subwoofer with Dolby Atmos - $499 at Costco
Vizio 5.1.4 Dolby Atmos soundbar system features a 2 front upward firing speakers and 2 rear upward firing speakers to allow for Dolby Atmos. Subwoofer + Rear speakers connect wirelessly to main soundbar unit.
Reviews on this model are overall very strong. There is an older model that is only 5.1.2 (no rear upward firing speakers) that got mediocre reviews in large part due to software issues. This model seems to have solved those problems.
This went for $480 last Prime Day but I've rarely seen it discounted.