These are all unbelievable backhands. Since surface is not specified, I'll just list them generally:
1) Djokovic- Unbelievably solid. Great variety. Never breaks down.
2) Murray- Much like Djoker's, just a touch weaker. Better slice, though.
3) Peak Fed- Insane variation, could do pretty much anything he wanted with it. Easily my favourite backhand of all time.
4) Gasquet- Like Fed, amazing variation. More power and spin than all of the above, but not quite as good on the defensive, as his big swing needs time on it.
5) Wawrinka- Imo the best backhand in the wolrd when on. Will blow anyone off the court. Butlike the rest of Stan; too inconsistent to be at the top.
6) Current Fed- A technically more acomplished shot than peak Fed's, but for physical reasons not quite as effective. For some reason doesn't seem to have the same confidence in it as he used to.
7) Zverev- For sure a solid backhand. But not on the level of the others(yet).