Omagh, written by Paul Greengrass and Guy Hibbert, and directed by Pete Travis.
I saw this film as part of the 2005 Atlantic Film Festival. It's based on the bombing in Omagh in 1998, several months after the Good Friday Agreement was signed. The Agreement was a huge step toward peace in Northern Ireland, and the Omagh bombing (a reaction by an IRA splinter group that disagreed with the Agreement) was the single worst incident in the 'Troubles', resulting in the deaths of 29 people.
This film's screening attracted me on two levels: I'm interested in Celtic things in general (enough that I spent a year in a Celtic Studies program, although my knowledge of modern politics is sketchy), and because the director was attending and discussing the film. I have to say that my reaction is much more to the film's content rather than to the work itself, and I don't feel too bad about that; one thing that Travis said afterwards is that he shot the film on a handheld camera partly to remove the audience's sense of seeing a movie. It was actors working from a script, but many of the families of the bombing's victims were involved in making the piece as accurate a recreation of the events and their aftermath as possible.
The bombing itself was almost totally unexpected, since Northern Ireland was anticipating peace as a result of the Agreement. Omagh was targeted very specifically in reaction to the Agreement--the town's population of Protestants, Catholics, Presbyterians, and Mormons lived very peacefully together, and driving them apart would have been a powerful gesture. One thing Travis mentioned was that in some ways the bombing undid some of the damage done by "Bloody Sunday" (see also: U2's song) in the '60s, which drove some people to join the IRA. The terrorism at Omagh, after the peace agreement, achieved the opposite effect.
Omagh reinacts the bombing in pretty horrific detail, but deals primarily with the victims' families, many of whom banded together to form the Omagh Support Group and demand answers from the government(s) and investigators. The investigation was found to have been handled badly, with some insiders suggesting that there was an agreement to avoid prosecution of the suspects to uphold the peace effort. The film does an excellent job of portraying the families' grief and determination for justice, without falling off the edge into melodrama, and the performances are solid. It's hard to comment on the cast, since the effect of seeing 'real people' onscreen was achieved so well. Travis was careful to emphasize that everything was done with the support of the majority of the families involved, and that the project would have been abandoned if they'd opposed it (which seems unlikely, since most of the film is devoted to their demand to be heard).