Light, only what's needed, and cheap. The drawback being it's hard to build and not exactly the most robust of creations. Buy a couple, you might need a replacement after a few crashes.

A bare-bones 3mm frame made for 3 inch propellers and 13xx or 14xx motors (m2 12mm mount).

An ultralight, yet sufficiently strong frame made for 3 inch propellers and 18xx class motors.

An ultralight, yet sufficiently strong frame made for 4 inch propellers and 13xx or 14xx class motors.

An ultralight, yet sufficiently strong frame made for 4 inch propellers and 22xx class motors.

An ultralight, yet sufficiently strong frame made for 5 inch propellers and 22xx class motors.

Aprox. weight: 35g

Note: This frame is a bit... flexy. It's not going to snap in normal usage, but it's not going to survive a hard crash. But hey, it's cheap! Buy two, rebuilding is a valuable skill.

An ultralight, yet sufficiently strong frame made for 5 inch propellers and 22xx class motors.

aprox weight: 45g

An ultralight, yet sufficiently strong frame made for 6 inch propellers and 22xx class motors.

Made for use with 5 inch propellers and 13XX or 14XX motors. 

Esitmated weight, ~30g.

Made for 13xx motors and ultimate lightness