Music-wise, I'm a bit unsure. I like almost every games' BGM a lot, but I think SA and PCB stand out as the two of my favourite ones. From those two, it could be any, but I think I'll pick PCB.
Scoring? I like scoring in several games, notable being PCB (I'm bad at it), IN (I'm somewhat bad at it), and UFO (I'm really bad at it). From these games, every scoring system has it's own unique trait. UFO has the possibility to pick either rescources or score, and you have to balance between those two, especially if you're not so strong when it comes to the survival side. IN has the phantom gauge and timepoint farming system, and I really like milking time for some reason. PCB has the borders. Border timing and spell card milking and damn, hard stuff man. I'd be in a trouble with border timing alone, but milking Yuyuko in addition to that? Aw hell, this game's hard. But it's fun, and the scoring system is indeed good. However, I think I'll pick IN, since I like it the most for some reason, even tho' I'm focusing on UFO at the moment.
Spell Cards? Both UFO and PCB have some strong ones in my opinion. PCB has a lot of scoring spell cards, and every card needs to be done in a reallly really badass way if you're aiming for good score. UFO has interesting Spell Cards, and has you moving around the screen on several cases, which I really like. I'd want to say PCB for Yukari alone, since I like her battle a lot, but I think I'll have to pick UFO for the overall cards.
Story? Uhhh. I did like PCB's plotline, and SA's storymode is fun to play every time when I'm not scoring. However, since I've mainly been scoring lately, SA has become a bit forgotten for me. But I don't think I'll pick either of these here. I'll pick IN. While I originally did not like the backstory that much, and the lunarian hazzle confused me, playing Magic Team easy made me realize how cute the dialogue and the endings were. Mokou's dialogue was also partially comedy gold, but it still didn't win Yukari's. But yeah, I'm picking IN because of subtext!
Shot types? I.... I like PCB's SakuyaB, IN's Youmu (even tho' it's hard to pilot her) and Magic Team, SA's MarisaB and..... UFO's MarisaA. Yes, I have no idea why I've been clinging to UFO MarisaA lately, since scoring with her is.... hard. I'm far from consistency in everything, but the game is enjoyable when I play her. I've been thinking if I should swap to some easier shot, but I want to try MarisaA more a bit. I like her, so I'm picking her here. I think I've been contaminated by Naut.
General feel? I... what's that? The mood? Well, in my opinion the theme always fits the games' and such. UFO is maybe not as tragic and not all the games are as serious business as others', but I still have to say, that every single game has rather good general feel around them in my opinion. It's really hard to pick anything here, so I'm letting this one fall empty.