I'm need know Best Luxury Small Car Selling in US? Please?

Acura TL
Audi A4
BMW 3-Series
Buick LaCrosse
Cadillac ATS
Ford Taurus
Hyundai Azera
Infiniti Q
Jaguar XE
Kia Cadenza
Lexus IS/ES
Lincoln MKZ
Mercedes Benz C-Class
Nissan Maxima
Volvo S60

The best selling is the BMW 3 Series. The best small luxury car sold in the US you can buy is the Cadillac ATS which is more dependable than the BMW and it a fantastic car.

From recent history, the BMW 3 series has been the perpetual best seller. The Mercedes C-class & Audi A4 (as well it's derivatives like S4 & RS4) follow close behind.
After the German big 3, the Infiniti Q50 (or the older G37 & G35) & Lexus IS follow close behind, with the Volvo S60, Acura TL & Cadillac ATS following suit. Of the cars that qualify as a "small luxury car" (read below for details), the Lincoln MKZ is the worst seller of the bunch.

Note several cars you named (e.g. Ford Taurus, Buick Lacrosse, Hyundai Azera, Kia Cadenza & Nissan Maxima) are not members of the "Compact Executive Class" sedans. All of the above are built on a conventional existing FF architecture of a cheaper car. They're closer to what America refers to as "Full-sized Sedans". They do however, occupy the same price range as the cars mentioned above and offer much more space per dollar, if not the luxury or technology of premium manufacturers.

P.S. As of writing, the Jaguar XE is not in production.

BMW 3 Series