The following diagrams show which assumptions are required to get which implications in the finite and asymptotic scenarios.

[![Finite OLS Assumptions][1]][1]

[![asymptotic OLS assumptions][2]][2]

I think it's important to think about not only what the assumptions are, but what the implications of those assumptions are. For example, if you only care about having unbiased coefficients, then you don't need homoskedasticity.


  [1]: https://i.sstatic.net/VUQAQ.png
  [2]: https://i.sstatic.net/7Fa14.png