My all time favorite actor is Oguri Shun (he is excellent in HYD, Yuuki, Hana Kimi, Juui Dolittle, Tokyo Dogs, and Rich Man, Poor Woman) my second favorite is definitely Matsuda Shota with Liar Game and Love Shuffle.
I also find these actors' talent above average:
Seto Koji (Koizora, Atashinichi no Danshi, Otomen, Rinne no Ame, Tumbling)
Eita (Nodame Cantabile, Sunao Ni Narenakute, Lucky Seven)
Tamaki Hiroshi (Nodame Cantabile, Love Shuffle, Guilty Akuma to Keiyakushita Onna)
Kamenashi Kazuya (Nobuta wo Produce, Yuuki, Yamato Nadeshiko Shichi Henge)
Yamashita Tomohisa (Nobuta wo Produce, Kurosagi, Buzzer Beat)
Matsumoto Jun (Kimi wa Petto, HYD, Smile, Lucky Seven)
Matsuyama Kenichi (Death Note, Detroit Metal City, Usagi Drop)
Kimura Ryo (Hana Kimi, Nodame Cantabile, Otomen)
Daito Shunsuke (Crows Zero, Tumbling, Ouran High School Host Club)
Okada Masaki (Hana Kimi, Otomen, Seinaru Kaibutsutachi)
Matsuda Ryuhei (Gohatto, Blue Spring, Ashita No Kita Yoshio)
Miura Haruma (Crows Zero 2, Samurai Highschool, Hi Wa Mata Noboru)