Sadden

A modern successor to JEI that boasts better performance and features, though many mods are still yet to implement dedicated support. It can piggyback off JEI support though that doesn't always work fully. This can be alleviated by installing TMRV to act as a bridge between JEI compatible mods and EMI internals. In time it's likely that most mods will implement inherent support.

Create is the mod that made its impact on modding by being one of the first to allow for large-scale automation while having great aesthetics along with introducing ponders as a way to teach mod mechanics which can now be used by other mods too.

Make sure to check out many addons and make sure to install performance mods, especially with shaders (Colorwheel is your friend)