Sodium is the one with the most impact, but there are other good ones out there. So its not just one mod, but multiple. https://github.com/NordicGamerFE/usefulmods/tree/main/Performance

If you want a modpack that gives you performance, check out https://modrinth.com/modpack/sop

simply optimized modpack

I don't know about best, but give Fabulously Optimized a try.

I dont have ready list of performance improving mods but I would look at mods installed by rlcraft. The modpack is so heavy on resources they tend to add many mods for performance improvement.

Sodium plain and simple. Its the Performance Mod.

Do Take a Look at others too though, not as a replacement but rather a complement.