The role of Beowulf belongs to Gerald Butler of Phantom of the Opera fame. Scottish brogue aside, Butler nails Beowulf as a person of destiny who attempts to understand the motivations of his enemy while questioning the motives of his allies. It is while he seeks to understand Grendel that he comes to realize there is more to the monster than the ferocious killer portrayed by the victims.
Grendel is ably played by Ingvar Sigurdsson. The actor imbues the troll with a single-minded goal of vengeance tempered with a primitive sense of justice and an innocent child-like quality that evokes a profound sense of sympathy. Sigurdsson has no dialogue, beyond grunts and screams, but still presents a multi-layered character through facial expression and body language. There is a particularly compelling scene where Grendel stands on a ridge, smashing a rock against his forehead, working himself into a battle-frenzy.
The supporting cast is generally strong, with the possible exception of Selma the witch, played by fellow Canadian Sarah Polley. A wonderful actor in many independent films, she is out of place here. The music score is good, though I found it jarring in parts. As previously mentioned, the Icelandic scenery is stunning and used to good effect--the frosty breath you see when the actors speak is real. The art direction and costuming is solid, the photography outstanding. One interesting note, the dialogue uses strictly Anglo-Saxon root words.
There is a sequence where Beowulf and his warriors wait during the night in Hrothgar's Mead-Hall for the troll to attack. It is very reminiscent of a similar scene in The 13th Warrior. However, that is where comparisons end. While the latter film is a good time-waster, Beowulf & Grendel shines as a gritty telling of the epic saga. Highly recommended.