If you are considering doing anything pixel art related or want to see
the pixels as they "truly are," you need to disable Mipmaps. You can do
this in the "User Preferences --> System" tab.

Disabling Mipmaps will also help a little with CPU/GPU resources. This
feature is similar to how game engines have bilinear/trilinear filtering
to "smooth" pixels of 3D models with low resolution textures.