Pain & Gain was almost good, but got to be a little much. I forget when I checked out, but I think there was a dwarf involved.
As a big tennis fan, I thought Richard Williams seemed like an interesting subject for a biopic, since he's a fascinating character. But I avoid biopics as a matter of principle so will probably never watch this.
Never Let Me Go was good (I didn't think the plot was that hard to follow, but I've seen it twice) but yes, bleak. Between this and The Remains Of The Day, Kazuo Ishiguro has a pretty strong track record of books being adapted into movies.
I barely remember The Other Guys except I think it was hit-and-miss.