Recently I`m a bit partial to 石田彰. He has some serious range... Females doing male parts aren`t all that rare, but males doing female just stuns me. In a good way, of course.

well i got to say Johnny Young Bosh-ichigo from bleach

such a great voice! lol :p

I thought he was great as the Black Ranger in Mighty Morphin' Power Rangers.

American - Vic Mignogna. Full Metal Alchemist got me hooked on him, and i just loved him as Kurz in Full Metal Panic! XD
and whoever does Renji Abarai. i don't know the guys name, but i think he just does an awesome job with him!

Japanese - Mamoru Miyano. Tamaki was just...amazing. i now absolutly luvv this guys voice. really makes me wanna watch Wolf's Rain, Vampire Knight, and Soul Eater

Steven Blum and Wendee Lee; Both Cowboy Bebop. x]

Greg Ayres (voice of Goku, Satoshi,and many more... and now the voice of Kaoru from Ouran High School Host Club... can't wait till it comes out ^.^), Quinton Flynn (voice of tons of people. Axel and Reno are my favorites), and Vic Mignogna (Edward Elric. I need not say more.) are my favorite American VA's.

this is dumb but i....idontknowmuchanime!!! *huh huh*
i like dante basco.:rheart: he does the voice of prince zuko on avatar....

Oh I love Vic Mignogna to death! He's my favorite, hands down. I'm also a member of his fan club. Go Risembool Rangers! :D I also like Johnny Young Bosh and Travis Willingham.

My favourite voice actor of all time is Rob Paulsen. He voiced Raphael (original Teenage Mutant Ninja Turtles cartoon), Pinky (Pinky & the Brain), The Mask (the Mask cartoon), Fowl Mouth (Tiny Toons), one of the Animaniacs and others I can´t remember. I think he has a great voice and usually voices great characters.
I really don't know the names of most voice actors, and usually I am not really interested in that subject.

Hard to narrow down...
 

English Voice Actors:
Maurice LaMarche...Vic Mignogna...Kevin Conroy...Mark Hamill...Paul Rugg...
Grey DeLisle...June Foray...Cree Summer...Tara Strong...Lenore Zann...

Seiyuu:
Inoue Kazuhiko...Sakurai Takahiro...Seki Tomokazu...Ueda Yuji...Yamaguchi Kappei...Yamadera Koichi...Kamiya Akira...
Hayashibara Megumi...Ogata Megumi...Sakamoto Maaya...Hidaka Noriko...Inoue Kikuko...Shimizu Saeko...Mitsuishi Kotono...