I tried Harbinger's demo once. It's okay, the characters are a bit tiny (not sure if I can change the setting to make them bigger), but I could not find the game in local stores, and I can't order anything online at this moment.
Never heard of Knightshift. I'll check that later. Thanks.
I've tried Eidos' Revenant demo, and Emurasoft's Shadowflare Episode 1. Again, both are okay in my opinion. The problem is just finding them locally.
I found this one:
Fate
According to a few review I read, it is quite good, but it is published by WildTangent, which some people consider as including spyware in the application, so I'm not sure I would want to try it. I've also heard about their strict unlock policy for those who actually buy the game.