16. Mazda Millenia S
The Mazda Millenia S is a standout from the ’90s executive car world, thanks to its innovative Miller-cycle supercharged V6 engine. This rare powerplant delivered smooth, efficient performance while maintaining refined luxury—at a price far below its European competitors. Originally intended as Mazda’s premium flagship, the Millenia S offered advanced features and plush comfort, but struggled to find widespread recognition. It remains a hidden gem for those seeking sophistication and engineering intrigue without the usual price tag.