Robert Duval was excellent in secondhand lions. Excellent movie and a real chance for true craftsmanship to show through.
I also very much liked him in Open Range.
Bit more terse, and didn't have a lot to say at times. But still Duval on a good day.
Lonesome dove was good, but if you really want the full range of what Duval can do, Secondhand lions is it. Its like the difference between a coffee blend, and a single straight full bodied coffee. It may give you a jolt, but you'll remember it.