Brunelli are the most treasured wines in my cellar. To me they offer the ultimate experience in complexity and depth.
Both come in different incarnations. There are the classic ones that often need quite some time (10-15 years) to balance out. They have significant higher acidity in their youth than most new world wines. But if you give them enough time they develop into wonderfull complex wines with a perfect balance. More modern ones can be very aproachable in their youth and still last (and develop!) for many years.
Right now almost all 1997 Brunelli would be a good start. And many 2001 are quite sexy in their youth right now. Avoid 1996 or 2002. Others might be able to give a suggestion for Barolo. I've only had a few.
Most of the time JS ratings and drinking windows are in line with my palate. A good source to find more information on these wines.
And, whatever you choose, don't decant a Brunello di Montalcino. It opens up much more gracefully when you leave it in an opened bottle and give it a few hours.