e9 and e24 owner
I have 1988 M6 (92K), 1987 635 (5 spd, 122K) + my 1973 e9 (the original shark).
The 1987 is my daily driver, but I drive the M6 a fair amount except in winter (PS2s). Both are very reliable.
Two of the most beautiful BMW designs of all time. Nice e24s are quite reasonable, very reliable (that M30 engine), and much less (but not immune) likely to rust than the e9s. You can even find nice reasonable M6s but these require a search (only 1700 US made, however, and although the engine is quite robust, any significant engine repairs will double the purchase price). The problem is most have over 150K so they need sorting. Like the e9s body parts are very expensive.