Fishgun because I love the premise surrounding it.
For the record, I want a F/A FS-2000.
>Light trigger press for semi-auto
>Hard trigger press for full-auto
>ambi safety
>mag release is pretty intuitive
>brass does not eject into your face
>controllable RoF in F/A mode
>dat HK style charging handle
I mean, what's not to love?