OptiCraft is modpack with 64 mods in it.
It's made to look the best. Great terrain generation, more biomes, amazing animations which can be turned off to each entity and mob, beatiful first person look, realistic trees, a lot of new mobs, better block placing and breaking, detailed grass and more...
(it's still on 16x16 texture so it still have the minecraft look but it is slightly better)
There is also mods to make the gameplay more enjoyable for example: dozens bosses, more tools and weapons or huge great looking dungeons to explore, new Aether and Twilight dimensions and more...
It's free to play so there is no hesitation to try it.
Also if your computer runs at low unplayable FPS
Try:
[in options > video settings]
turning off "Entity shadows"
Set graphics to - Fast
turn clouds to - off
particles to - minimal or decreased
Render distance to - 2 chunks
[in coptions > controls]
Find "Fancy block animations" and then in game press the button you binded on and in upper right corner click on disable fancy particle
Also try "Mo' Bends" in game press M and every animation to each mob turn off which
Please excuse my bad english and enjoy the modpack!