This thread always comes up and since I've already thrown together a thread for the main party, I figure I'd put up a thread to guage people's impressions of the lead females - Luna, Iris, Cindy, Aranea and Gentiana. And any of the other girls (eg. Coctura apparently has a fan following based on my short time browsing reddit earlier on).
For me...
Endgame Spoilers
Luna - Clearly someone who has accepted her bloodline completely. I liked her well enough. She seems to be a true strong-hearted matron like figure. We don't see a terrible amount of her and it's basically 100% cutscenes, but they pretty much nailed on her heal-the-world style personality, her love for Noctis and I enjoyed her and Noctis' memories. I felt they really got the children written well, which is pretty rare in my opinion. I like that SE had the guts to actually kill off the love interest (let alone the main character too).
Cindy - I thought she was one of the best written female characters, although it's 90% taken care of in the early chapters. She doesn't seem to fit any common stereotype for video game characters, laughs it off when she hears about Prompto's interest, has a small bit of backstory but for a non-main character she was reasonably fleshed out and, despite all the worries about her looks, turned out not to have any personality issues.
Iris - My favourite of the lot when it comes to the various obvious "harem choices" that the game seems to have provided. I felt she was adorable. That little 'date' and the moogle thing, her riding in the back with the guys, her open conversation during fights and her ability to actually tag along with your crew and omg I wanted to keep her in my party forever just so I could have someone who can restore Base HP. She was the real white mage in this game, gameplay-wise! I spent a good length of time just running around beating up monsters etc. with her as a 5th party member constantly topping up the gang. For someone with minimal HP compared to everyone, she managed to never die. 10/10 would party up permanently if it was made possible via DLC.
Aranea - Best voice in the game. Sassy. I liked her a lot. And damn, her tech bar limit break thing was AWESOME. 9999 damage dragoon jump? Oh yes please. She also whooped my butt the first time I faced her so gets mad respect there, it was one of the first times I actually had to make a much more careful and tactical use of all the battle tricks.
Gentiana - Cool how she revealed herself. But overall she seemed like a fairly robotic character.