Here are some more seiyuus for you. From now on I'll try to add more seiyuus with a common theme in them, you'll be able to see so from the title. Though this batch of picks were rather random in my opinion...
I swear to god she needs more roles. She doesn't have a lot of roles compared to most of the other awesome female seiyuus BUT SHE NEEDS MORE. She has one of the most tsundere-ish seductive voices in the voice acting industry, and when she goes all out its SUPER hot. All of her voices have this sexy tone to them, which makes it seductive. Chihaya (Idolm@ster), Kurisu (Steins;Gate), Tsubaki (Blazblue), Ikaruga (Senren Kagura) and Noire (Hyperdimension Neptunia) have all her default tsundere-ish voice. Her more "mature" tone comes from Cecilia (Atelier Totori) and Kiryuu (Kiss x Sis). Ayumi (Corpse party) and Solva (Needless) share a lot of similarities. Normally they are both sweet girls, but darkening Ayumi and crazy mode Solva become psychotic bitches right away.
FUAHAHAHAHHAHAHA! That's Mamoru Miyano in a nutshell. Other than voices mostly bijin characters, he has a pretty badass voice which he will use for certain characters. Bijin character VAs are everywhere and almost all the guy seiyuus can do it, but it takes something special to do the voice of a maniacal mad scientist in Okabe (Steins;Gate), a badass scheming motherf**ker called Light (Death Note), and a power hungry bastard, Saruhiko (K). Death the Kid (Soul Eater) was also pretty badass, but he was laid back in the same time, kind of similar to Kida (Durarara!). Riku (Kingdom Hearts) is just bijin, similar to Flynn (Tales Of Vesperia), though Flynn has a more "gentle" side to the voice.
What can I say? Seiyuus who voice loli characters have ridiculously cute voices. Even though I'm not one to fap to lolis and flat chested girls, I still do think having that incredibly cute is a plus to most characters that look cute. Yui Ogura is stupidly young (she's 19, I believe), and the characters she voices have VERY cute voices. Since she is still fairly young, she doesn't have the diversity, but I can work with some moe. My favorite of her characters is Alice (Kamisama no Memochou), and Kuroe (C3:Cube x Cursed x Curious)is a very close second because of her kawai personality. She didn't get much screen time, but she did voice Choco (Mayo Chiki). She can do a "villain" as well with Athena (Campione) and Hinata (Ro-Kyu-Bu) is probably the cutest voice she has done yet....
If you don't know him you're not an otaku. Daisuke Ono is probably one of THE most highly regarded seiyuus in today's anime industry. He has done an EPITOME of famous characters, including the favorite of all fan girls around the world, Sebastion Micheals (Black Butler). His versatility is crazy high, and he can do very different voices, sometimes you wouldn't know its him. His calm, bijin voice is probably the most liked among his many others, characters like Koizumi (The melancholy of Haruhi Suzumiya), Sebastion (Black Butler), Kuroh (K) and Satsuki (11eyes) fit nicely. Then you have the slightly louder, shonen hero type voices like Snow (Final Fantasy XIII), Arthur (Ao No Exorcist) and Tenzou (Kyoukai Senjou Horizon) fit the bill. However, his badass voice is the best, Jotaro (Jojo's Bizarre Adventure), Shizuo (Durarara) and Battler (Umineko) are all f**king awesome characters.
He can basically voice any bijin/bishounen type character in the world, he just has that perfect bijin voice. Like almost most of his characters are freaking bijins, what the heck? ALMOST ALL OF THEM SOUND THE SAME! He has his main character/helpful young man voice in Otonashi (Angel Beats), Hibiki (Devil Survivor 2) and Koyomi (Monogatari Series). He has his share of badass voices, though they don't sound too different from his main character voice, Levi (Shingeki No Kyojin) and Lilio (Black Rock Shooter:The Game) come to mind. Then we have his "bad guy", "scheming bastard" voice in Izaya (Durarara) and Mephisto (Ao No Exorcist).
Another versatile voice actor!....Sort of. Eri Kitamura has voiced some of my absolute favorite characters, but she has so many tones to her voice that I find it hard to believe at times. She sounds best while tsundere, in my opinion, because there are actually different tones to different seiyuus when they have to do tsundere characters, Eri Kitamura's tsundere voice is excellent! See Cordelia (Atelier Rorona/Totori) and Liliana (Campione), you'll get what I mean. Her ojou-sama voice is also pretty good, characters like these are Kanade (Mayo Chiki) and Ami (Toradora). Karen (Monogatari series) sticks out like a sore thumb because she's the most normal girl out of all she has voiced. She has her share of cute airheads like Yuka (Corpse Party), Eve (Needless) and Yui (Angel Beats). Juri (Super street fighter IV) and Nikaido (OniAi) are are fierce voices.
Probably more to come. Peace for now.