Best ROI plugins?

Hello to everyone
Hope you are doing great even with this whole virus situation.
For this occasion, I wanted to know your opinions on the BEST plugins in terms of their return on investment.
In other words, which plugins can help you make AT LEAST their monthly/yearly cost.
I'm on a very tight budget and looking for ways to speed up a website's growth, which doesn't mean i can't invest a little into the project.
The more the merrier, appreciate any suggestions you could do

You need paid plugins in very rare cases according to me unless you are running eCommerce sites. As most of the required ones, you can download from BHW.

Nut-Nights said:

You need paid plugins in very rare cases according to me unless you are running eCommerce sites. As most of the required ones, you can download from BHW.

Click to expand...

Which ones would you catalogue as "required ones" and where could I get them o: