TechArmor from Amazon.
Not the cheapest, but not as pricy as PowerSupport and Spigen.
Fantastic.
Put their Antiglare on Girlfriends iPad Mini Retina.
Have their Clear HD on my iPad Air.
Have PowerSupport Clear on my iPhone 5.
And Had PowerSupport Antiglare on my previous iPad and iPad 3.
Can't tell a difference PowerSupport to TechArmor.
They go on the same way, they both lift easy with scotch tape to grab dust. They match up almost exactly.