Well I do agree that Bug is one of the best (American) films of the year, and I will also agree that The Exorcist was a "terrible experience", and for that reason, The Exorcist is one of my favourite films of all time. 

Bug convulses with mania throughout. I loved how the film played on so many levels, including humour with the blackest of hearts. The ones I manage to get in that single screening of the film was psychosis and loneliness, a probable cautionary tale on crack and a examination of corporations and government selling to us unseen terror and foregone ideas of danger when paranoia and misinformed delusion strikes the carefully calibrated chamber piece. The real genius of the film is that the moment we start to believe the characters (made all the more easier with ace work by the cast, especially Harry Connick Jr.), is when the film starts to work and click into gear.

To me, it's a near masterpiece of mood and tone. Friedkin's best work in ages, and has an edge and energy and a precise focus about it that works on an intelligent and visceral level. It manifests its characters' buried thoughts and hidden fears into a climactic blowup with Ashley Judd's awesome monologue. It becomes a collective descent into madness that ultimately includes its audience as well, and actually recalls the clockwork horror in the denouement of The Exorcist where hope is sapped and the entire tone evokes mutual doom.