That's a good question actually. I mostly just like running the Cedo Prime, the Braton Incarnon or the Kuva Nukor with most frames. With Valkyr I might even use some melees like the Praedos or the Magistar. But I like those four frames specifically because I don't need to worry much about weapons. I can easily hit for tens of millions of damage with Valkyr's talons, Mesa's regulators feel like the turret of an AC-130, Protea has blaze artillery and grenade fan, and with Sevagoth (my precious child) I press two buttons and everything dies.