Everytime I choose an anime to watch, its in my list who are the voices behind those characters.
Let me share my favorite Seiyus
Kamiya Hiroshi - Akashi Seijuro (Kuroko no Basket), Trafalgar Law (One Piece), Yato (Noragami)
Akira Ishida - Athrun Zala (Gundam SEED/Gundam Seed Destiny), Katsura (Gintama)
Kaji Yuuki - Eren Jaeger (Shingeki no Kyojin), Yukine (Noragami), Mabuchi Kou (Ao Haru Ride)
Yamaguchi Kappei - Ussop (One Piece), Inuyasha (InuYasha), Shinichi Kudo (Detective Conan), L (Death Note)
Just thought I'd get that one out of the way for everyone. She's popular for a reason though... such an awesome voice, for characters who are both strong or weak. Also, best imouto.
yeah... youre right.. she's really great...i came to like her more because of Rize (Tokyo Ghoul).
Izumi Kitta , she did the MC in Watamote. One of the best voice acting perfomances I have come across for a female.
Jun Fukuyama> most recent perfomance as Koro sensei from Ansatsu Kyoshitsu. He's done plenty of other stuff too like the MC guy in Chuunibyou, Grell from Black Butler and Kimihiro watanuki in xxxHolic. I could listen to this guy's talent all fucking day
Probably not as popular as Kana Hanazawa^ but imo she deserves just as much attention>> My favourite is the flawless Marina Inoue. Her voice has a wide range: from the adorable and spunky Kana of 'Minami-ke' to the renowned Armin Arlert in SnK--she is hands-down awesome. (I first came across her when she performed a perfect interpretation of Kyouko from 'Skip Beat!'~) (๑^っ^๑)
Only Seiyuu worth caring about, Nana Mizuki

Fukuyama Jun - Koro-sensei (Ansatsu Kyoushitsu), Liberta (Arcana Famiglia), Kazuki Mutou (Busou Renkin), Lelouch (Code Geass), Nura (Nurarihyon no Mago), Kei (Special A), ...
Romi Paku - Hitsugaya Toushirou (Bleach), Tao Ren (Shaman King), Temari (Naruto), Edward Elric (FMA), Natsume (Gakuen Alice), ...
Miyano Mamoru - Yagami Light (Death Note), Taichi Mashima (Chihayafuru), Chrollo (Hunter X Hunter 2011), Tamaki Suou (OHSHC), Shoutarou Fuwa (Skip Beat), Kiryuu Zero (Vampire Knight), Ichinose Tokiya (Utapri), Shuu Tsukiyama (Tokyo Ghoul), ...
Kugimiya Rie - Alphonse Elric (FMA), Happy (Fairy Tail), Kurosaki Karin (Bleach), Kagura (Gintama), Masako (Ghost Hunt), Shana (Shakugan no Shana), Louise (Zero no Tsukaima), Juuzou (Tokyo Ghoul), ...
My seiyuufu is Toyosaki Aki. Her voice heals my soul every time I have the pleasure of hearing it.

Welp, I know just which TLR character you would end up falling for.
...speaking of pleasure...
Miyuki Sawashiro's voice is the only one for me. Goddamn, I'll watch everything she's in even if her character is a walking ass crack .(Cough) Shinon (cough) <3 But some other characters are great like Celty (Durarara!), Kanbaru (Monogatari Series), Saeko (HOTD), Kurapika (HXH).
Some others that I like are HanaKana, KAmiya Hiroshi, Chiwa Saito
Have some MIyuki Sadistic greatness. ;)
Female seiyuu:
Kobayashi Yuu -- Sasha Blouse (Attack on TItan), Shidou Mariya (Maria Holic), Clain (Fractale), Ruka Urushibara (Steins;Gate)
This lady has hella sexy voice. Not the moe-sexy (which is not sexy at all) but adult-sexy, if you get what I mean... I'll watch any anime she's in no matter how minor her role is! :D
Also her singing voice is not bad at all: (A little bit NSFW. Be sure to wear headphones!)
Male seiyuu:
Ono Daisuke -- Sebastian Michaelis (Kuroshitsuji), Itsuki Koizumi (Suzumiya Haruhi series), Shizuo (Durarara!)
This gentleman also has a hella sexy voice. Even his normal speaking voice is also sexy <3
Takehito Koyasu
Always think of Dio when I hear his voice, what a legend.
Also he's in like half the anime that I watch lol
Male? Yoshitsugu Matsuoka. This guy is the most generic protagonist in existence, voicing the heroes of Danmachi, Sword Art Online, Eromanga-sensei, Shokugeki no Soma... but then suddenly, a wild Petelgeuse from Re:Zero appears! Or Inosuke from Kimetsu no Yaiba that's pretty much wild screaming all the time! Or this pearl:
If we also include female (f##k if I know whether you people call them actors or actresses these days), then it's hands down Aoi Yuuki. I don't think she has a single voice that sounds like another one she did yet.
The maniacal Clementine from Overlord, the croaking Tsuyu from My Hero Academia, the sweet little Madoka from Madoka Magica, the tiny general Tanya from Youjo Senki, Tatsumaki from One Punch Man...
This is Talent. With a capital T. There's literally no voice actor or actress better than her in my opinion. I worship the hell out of this woman. She is brilliant, absolutely fantastic!
The fact that Matsuoka has that incredible range (as shown in his appearance as Petelgeuse) but then decides to take the roles of literally every boring harem MC makes me a bit mad. But a man has to make money I guess...
(I also really liked his voice acting for the MC of NGNL Zero and bits here and there from the regular NGNL series)
i dont really have one, but ill just go with Yuu Kobayashi cos her screaming is cute
Only Hiroshi Kamiya can voice the protagonists of great anime series such as: Monogatari Series, Arakawa Under The Bridge, Sayonara Zetsubou Sensei, Noragami, Saiki K., Kakushigoto, etc. He really makes every character that he plays his own with that very particular voice that he has. You can recognize him instantly.