The glamour and brand equity BMW enjoys today has largely been created by the original 3 series the so called '02' (pronounced 'oh-two') in the late 70s as the original and definitive compact sports sedan. The company went further and further and eventually ended up building something called the M5 (E28) which represented the original super-sedan.
The range of cars that ultimately catapulted the marquee into the upper echelons of the automotive industry though were the boxy and ultra qualitative 3, 5 and 7 series models of the late 80s and early 90s namely the E30, E34 and E32.
Above is an SLR shot of a 1991 730i E32 7 series I used to own. The headlights were actually shared among all three classes and singlehandedly defined the look that people think of when they hear 'BMW' - quite a feat.