I buy wine barrel chunks. They put out a wonderful smell, good enough that you want to eat the wood chunks. Gotta figure whiskey barrel chunks would be equally nice
I used some on a Brisket a while back - Got the Jack D. Aniels (you know the name) barrel chunks.
It's basically oak with a kiss-o-sweetness from the corn-squeezin's
Also tossed a few in the smoker box on my gasser when cooking-up some steaks
I got some oak barrels from down south that were used for whiskey and then for beer. I chunked up a few pieces and tossed in the coals this weekend when i did a 9.5lb butt. Came out quite delish! I think i've found my new favorite aside from cherry wood.