Piggy-backing off the brilliance and success of the previous shader pack on this list, Complementary Shaders is an offshoot of BSL Shaders, designed to be 'as issueless as possible'.
The fact that Minecraft can look this good and still run at a solid 60 FPS on a decent rig just blows my mind. It actually runs a little better for me on my (high-end) rig than the other 'go-to' shaders on this list (Sildur's and SEUS). You might expect that such stonking pulchritude comes at the cost of lower frames, but. Plus, you can turn on World Curvature for some wonderfully unique screenshots. Everything included here, from the amazing depth of field effects to the crisp lighting, the beautiful water reflections, and the fluffy far-off clouds utterly transport you to a place that you could almost imagine to be Minecraft 2.0.
In fact, when all's said and done, this is the shader pack that I always go back to for my own survival worlds, as well as any Minecraft servers I frequent.