Oh gosh, you shouldn't have done this. XD Now, prepare for the rant of a lifetime, because no joke, I'm going to discuss every idol there is.
Meaning 961, 876 and 765.
OK!
Heeeeere we go...:
Ai: I like Ai's voice, but it's not one of my favorites. She can sing, and she's fabulous at it, but sometimes she just...I don't know, belts too much? Which is odd considering my adoration of Makoto's angelic voice.
Yayoi: Yayoi's voice...I'll be honest, it's my least favorite. I mean, she's cute and all, but high notes just don't seem to work with her, and sometimes I feel like she struggles to carry the tune properly...? I don't know, I love Yayoi and all, but her voice is just "meh" to me.
Touma: Time for the rabid fangirls to come rip me to pieces. Ho boy.
I'm sorry guys, but I'm not a fan of Touma's voice. It's just...awkward to me. Like, you know that thing that lots of Japanese male singers do where they just...it's like, they sing from their throat. I dunno, his voice is nice, but it's not my favorite by far.
And is it just me, or does he sounds really similar to Hokuto in some songs...? Except Hokuto is less throaty and a bit deeper.
Ami/Mami: I'm being totally serious when I say I love the twins' voices. I know they, like, can't sing, but I just...when I listen to them, I hear a really beautiful voice buried under that...twin-ness. When they sing songs like Tonari ni..., Aoi Tori, or Futari no Kioku, that voice comes out better than ever, and it's just really beautiful.
Azusa: Azusa's voice is gorgeous. But sometimes I want to hit her with a bus.
Woohoo, I'm angering people left and right. It's called an opinion. I respect yours.
But, I dunno, sometimes she's just TOO soft, and it's TOO much vibrato, and it's TOO pretty. Like in a song like Overmaster. Just...I don't know. I adore her voice, but in some songs, I just...can't do it.
Haruka: Haruka. HARUKA.
I like Haruka a lot. She has a lot of songs that are just lovely. Moonlight Densetsu, Looking for Love, and both her solos on the Namassua Special 04 album are just incredible. But with some songs, I feel like Haruka is just...awkward. You know? So, I like her, but not as much as the twins or Azusa.
Hokuto: Hokuto's voice is gorgeous, but sometimes I feel the need to whack him on the arm.
I dunno. He just has his Touma moments.
I best go put on a suit of armor before the fangirls arrive. But I like Hokuto's voice more than Touma's, it's deep and smooth and pretty.
Iori: I really like Iori's voice. It's cute, it's pretty, it's intense, it's wonderful. I guess the only reason she isn't higher on my list is because her voice can get a bit...boring, almost? Like she just sings what's written, flatly. And that doesn't stop her from having a fantastic voice. It's a personal thing.
Ritsuko: Ritsuko's voice is actually my...eighth favorite out of all the ones I've heard. It's unique. I feel like a lot of times, she's just trying too hard to be something she's not, but then you hear something like 1/6 no Yume Tabibito 2002, and you're like "...*U* SERENADE ME MORE ANGEL." I just like her a lot.
Ryo: Let's get real, guys--Ryo's voice is fabulous, whether he's singing as a man (like in DREAM) or like a girl (like in Dazzling World). His voice seems to have a nice balance of strong and soft, and he's decently versatile.
But, like Haruka, he's just...awkward. And that vocal awkwardness prevented him from reaching my top six.
Yukiho: I like Yukiho, but...sometimes, she's just too soft. Personally, I prefer her Yurika Ochiai (first vision) voice more than her Azumi Asakura (second vision) voice. It just seemed...stronger. But that doesn't stop me from adoring her voice to no end in a LOT of the songs she sings.
Shouta: Shouta has my favorite Jupiter voice. I mean, his voice is really versatile (listen to his Alice or Guilty and then Jupiter's version of Do-Dai and try to tell me I'm wrong), and it's smooth and pretty. It's just nice.
Also Kirito. XD
While I'm on that subject, I ship Ai and Shouta just because of Kirito and Asuna. XDEri: Eri has the voice of an angel. It's so soft and gorgeous. In fact, the only reason she's seventh on my list is because I just adore my top six too much.

But she has these soft, lilting vocals, and this beautiful voice, and I just love her.
But remind her to never, EVER sing like she does in HAPPEACE ever again. She tries too hard to be cute, and I just...don't like it.
Now onto my babies, not necessarily in order, except that Makoto is last and I ADORE HERRRRR <3:
Hibiki: Hibiki. HIBIKI. I love Hibiki.
Her voice is so...great. I mean, no matter what she sings, she sings it well. ..Except Here We Go!!, that one was terrible. Well, not "terrible", just...yeah.
I just really like Hibiki. She sings with so much energy. <3
Miki: When Miki sings in her "emotional voice" (thanks for that, Wrath, I'm using it), it's probably more lovely than Hibiki's to me. I mean, when Miki is getting really emotional and just singing her heart out, I wanna cry because amazing.
But her over-emphasis of "I"s is just...ear-shattering. Sometimes, as much as I adore Miki, I want to smash her head with a baseball bat.
Takane: What can I say, Project Fairy is lovely.
I adore Takane's voice. It's a bit husky and can get awkward, but for the most part, her thickness and the beauty of her voice is just fabulous. <3 I can't say much more.
Kotori: KOTORI COUNTS OK.
I. Am in love. With Kotori's voice. (But not as much as with Chihaya or Makoto.) Seriously, she's my third favorite. Her voice is just so pretty! I love listening to her sing, she has such a soothing voice, and it's just...beautiful. I wish she sang more.
Hnnng, Kotori. <3
Chihaya: If Chihaya weren't in my top six, I know at least nine people who would kill me. Thankfully for me, Chihaya's voice is very easy to fall in love with. It's just so smooth and gorgeous and magnificent and I just love her. XD The only reason why she's not at the top is because Makoto is perfect. <3 <3
Makoto: Ho boy. Here comes the gush.
Makoto. MY BABY. MY. BABY. <3 <3 <3
I just...I just adore Makoto's voice! I know in some songs she like, can't sing. At all. (*cough cough Start Star cough Do-Dai cough cough Kiramekirari cough*)
And then.
AND THEN.
THEN YOU LISTEN TO ALL THESE OTHER SONGS SHE SINGS AND SHE'S JUST
The ONLY style of song I've ever not liked her in is the cute style, and even a lot of those she's amazing in! But have you ever just listened to her sing, like, really listened? (Kyun! Vampire Girl, Futari no Kioku, Swallowtail Butterfly ~Ai no Uta~, Megare (not the full version, as perfect as that one is.

))
She puts SO MUCH emotion into the emotional songs, her voice is smooth and gorgeous in pretty songs like Futari no Kioku or Tonari ni... (OK, not Aoi Tori, that one's not good), and I'm a sucker for deep, thick, alto voices. I'm so impressed by her range, and...
My final argument?
THIS.(I know it's Manual Vocaloid, but I mean, come on, it sounds JUST LIKE HER, and they take existing voices, so...)
And thus ends my Super Rant of Really Long Gushy Ranting.
Now, to take cover. *hides under a metal bridge*