Note: all of these are Fabric mods. You will need to have FabricMC installed to use them.
Sodium (huge performance boost)
Sodium Extra (more sodium options)
Gamma Utils (gamma modifier, fullbright)
Xaero's Minimap (minimap mod)
Xaero's World Map (full screen extension to above mod)
Appleskin (shows saturation, really good for pvp)
Replay Mod (this is required if you're a youtuber)
Shulker Box Tooltip (shows shulker contents without having to place them)
Essential Mod (multiplayer without a server, like inviting friends in bedrock edition)
Iris Shaders (this is a shader loader, for using shaders you still need to download a shader pack)
No Darkness Effect (removes the annoying darkness effect from wardens)
Simple Voice Chat (in-game voice chat)
Just Enough Items (shows all crafting recipes, including modded ones)
Zoomify (zoom mod)
Nvidium (more performance boost for Nvidia GPUs)
Chunky (pre-generate chunks for a minecraft server so that players loading chunks with elytra doesnt create lag)
Low fire (stops you from being blinded while on fire)
No Pumpkin Blur (removes carved pumpkin overlay)
Complementary Shaders Unbound (if you want shaders - Iris Shaders mod above required)