What is the biggest Ipad Currently?

The iPad Air 2, which is 9.7 inches diagonally.

iPad Air 2 128gb

The iPad, iPad 2, iPad 3, iPad 4, iPad Air, iPad Air 2 all have the same screen size of 9.7" diagonal measurement. Maximum storage capacity (if that's what you mean) is 128 GB.

See: https://www.apple.com/ipad/compare/

Bear in mind that 128 gig is before the operating system. I think you end up with roughly 120 of usable space (someone with one can tell you for sure, however a 16 gig iPad has roughly 12-13 gig is usable space. My 32 gig iPod has about 26-27 in usable space, so you lose some. And the amount you lose gets proportionately larger as the drive gets larger.

Basically, just know that you lose some.

By "biggest" are you referring to screen size or storage space? I just bought an iPad Air last month with 128GB of storage space.

114GB