I have to say, most of the cast is really enjoyable. The only downside is that many you don't get to interact with very much. For me it's a shame you really don't learn much about many of the characters and organizations. I still not entirely sure what G22 is, though I never did finish their dossier.
The characters that stood out for me were:
Marburg - amazing dialogue and conversations.
Leland - was wary of the time jumping narrative, but the conversations with Leland were really enjoyable. Played the villain very well.
Omen Deng - wish you had more interactions with this guy. I love his design, it's a pity he lost the cape halfway through. From what I read, his original design was that he was so skilled, he only ever used his left hand to fight.
Heck - hated the guy when I first met him but he grew on me.
Albatross and Sis - a very interesting duo that didn't get fully explained in my run.
The characters that underperformed:
Madison - I also felt this was a bit of a railroaded romance. I didn't care for her that much, but the game makes her death out to be some big emotional event.
Darcy - was disappointed since I felt this relationship had much more potential. Especially since he was tasked with hunting you down after you enact Alpha Protocol.
Michael Thorton - actually, he's not that bad, he just doesn't keep up with the rest of the cast.
I was going to mention Mina and Scarlet as poor characters too because some of their actions didn't make any sense but after a bit of research I realized I missed some of the big reveals of the game.
Edited by BEES, 04 June 2010 - 11:12 PM.