Which GPUs are the best relative to the amount of heat produced and/or electricity used?

I haven’t delved too deep regarding the 5090, but from my brief understanding, it performed better than the 4090 but also uses up an approximately equally higher amount of electricity relative to the increased performance.

Additionally, it also seems to maintain a fair temperature, but again, from my limited understanding, its temperature maintanence is due to increased fan cooling and not necessarily because it efficiently heats up less.

Regardless of how accurate the above statements are, it has got me thinking: which GPUs perform very well when running games while not using a high amount of electricity or producing a lot of heat? relatively speaking of course.

In other words, if GPUs had electrical/heat “efficiency” metrics described as quality frame generated per kWh and/or quality frames generated per joules (or is it joules per quality frames generated?), which GPUs would perform the best?