Keep in mind that everyone has their own parameter by which they measure.
My favorite parameter is longevity. Others, however, only consider power, or only consider economy.
If you want power, an '86 or '87 in good shape with the trap oxidizer properly removed would be a good car.
For reliability/longevity I still like the 123 cars.
The 124 diesels have an aluminum head which takes something away from the "tough as an anvil" nature of the 123's.