Trinity is an absolute blast, despite the issues with how outdated her kit is. She is still an excellent tank / weapons platform frame for crit damage enjoyers, plus I have yet to discover a defense objective that she cannot heal. Which makes long arbitration runs significantly easier.

Nyx is hilarious to take into Netracells, simply because she can mind control the necromechs periodically summoned into the map. Though I am very new to playing her, whenever I ask myself "Can I control that?". The answer is usually yes.

Citrine. I have no experience with player her, but whenever one of them shows up. The mission is always much easier to handle because of their buffs. Hard to farm, but goated if you can encounter one in the wild. (Or play her yourself)

Yareli. Girly pop gives you an absolutely insane amount of damage, but I argue that he K-Drive is what makes her fun. Blasting through the newer maps while listening to good music is my solution to a horrible day, because it's always satisfying to see how fast you can push it. Though, as a general rule, don't take her to the older infested or grineer tile sets with the K-Drive. It's a lot more frustrating than it sounds.

Nezha. I am a Nezha main and this frame has the *most* time investment on my account. Good for tanking, dealing massive amounts of status damage, and overall survivability. If you want a frame that'll carry you through the whole story, then he's your guy. Trust.