What are all of the "big" mods? are they actually good?

i mean stuff like mekanism, create, projecte, botania, ars, etc. i want to learn these mods so im gonna do it in one of the best ways imo; throwing them into a modpack and having their wiki pages open.

flairing discussion rather than looking for mods since i think that this could be an interesting thing to talk about

https://redd.it/1uljpw0
@MinecraftModded