For the 'wow' factor, I find searching for interesringly named mods by TenPlus1 and Wilhelm, is pretty effective. There's a bunch of interesting monsters and creatures across their mods.
It's worth sharing that I learned from previous experiences modding Minecraft not to push my luck with too many mods at once. I had to unlearn that, for MineTest.
Since MineTest was built from the ground up for modding, I've found that I can have a ridiculous number (dozens) of mods running together without any issues, as long as they're bug free and up to date mods.