Hellboy (1) looks really bad on Blu-Ray. The graininess is off the charts. I couldn't even watch half of it because I was constantly irritated from the bad quality.
Grain does not make a movie "look bad." Film, which most movies are shot on, inherently has grain. It is naturally there. If you use DNR to remove the grain, you remove the fine detail as well because the fine detail is actually stored in those film grains. So you have the choice of either watching with grain and getting the full detail as seen in the theaters, or you can DNR out the grain and get effective lower resolution and a video-like look.
Personally, I far prefer grain & theatrical-like look than trying to DNR everything (losing fine detail in the process) to look like a video game/wax museum. Film grain is to Blu-ray what "black bars"/widescreen was to DVD; it takes some adjusting to, but in the end you are getting higher quality with the grain intact. There is little point to high resolution/Blu-ray if you filter out tons of fine detail.