I've made some decent progress in Botania... having created the Terrasteel Agglomeration plate, I believe that surpasses what I've done before. It set up a wheat farm on my hill for the seeds required, automated by MF Reloaded Planter and Harvester. To make things more interesting and to pursue a few mods I was acquainted with, I decided to add in Ars Magica 2, Dragon Mounts, and Mo' Creatures.
Ars Magica is a magic system I dabbled in before but did not make much progress in. It seemed more interesting than Thaumcraft and more intuitive as well. I have the basics set up on my second floor.
Dragon mounts allows you to create eggs that the titular flying lizards bring into being. There are several types possible, IIRC based on the environment the egg is hatched in.
Mo' Creatures is a mod that adds a bunch more things that want to kill you, but from what I've seen it's not unbalanced. The hp on the monsters are reasonable at least. As a result, the lands around my tower are prowled by werewolves at night. Makes things interesting.