My favorites:
Minato Kageaki (Muramasa)
Saber (FSN)
Others I loved:
Himura Yuu (ef -fairy tale of the two-)
Kurapica (Hunter x Hunter)
Kuwabata Takuma (Swan Song)
Kuzuki Souichirou (FSN)
Miyagawa Takanori (Akatsuki no Goei)
Mystearica Grants (Tales of the Abyss)
Nirie Sumika (Harukani Aogi Uruwashi No)
Oscar Francois de Jarjeyes (Rose of Versailles)
Sagara Sousuke (Full Metal Panic!)
Sakaki Yuka (MinDeaD BlooD)
Solid Snake (Metal Gear Solid)
Squall Leonhart (Final Fantasy VIII)
Stein Heigar (Infinite Ryvius)
Others I liked:
Aiba Kouji (Infinite Ryvius)
Ange (Umineko)
Aoi Sena (Chaos;Head)
Arashi Kishyuu (X TV)
Athrun Zalla (Gundam SEED)
Auron (Final Fantasy X)
Ayane Ichijou (Muramasa)
Bazett Fraga McRemitz (Fate Hollow Ataraxia)
Benawi (Utawarerumono)
Chris Lightfellow (Suikoden III)
Fakir (Princess Tutu)
Fione Silvaria (Aiyoku no Eustia)
Gotz von Berlichingen (Dies Irae)
Himuro Kyoko (Eve -burst error-)
Hisui (Tsukihime)
Ichiotani Shiyuugen (Ayakashibito)
Kazaoka Mari (White Album 2)
Kogasaka You (Hoshizora no Memoria)
KOS-MOS (Xenosaga)
Kraft Lawrence (Spice & Wolf)
Lenneth (Valkyrie Profile)
Lightning (Final Fantasy XIII)
Mikami Teru (Death Note)
Minatogawa Tamami (Moshimo Ashita ga Hare Naraba)
Natsumi Rikako (Parfait)
Remi (Growlanser IV)
Ren (Extravaganza)
Touka (Utawarerumono)
Tuxedo Mask (Sailor Moon)
Visual novel & other stuff impressions 