There can be only one. The General Sherman Tree (Wolverton Rd. off Generals Hwy.) is the largest tree known on the planet. At just under 275 feet, it is not the tallest tree, nor at 2,200 years old is it the oldest, but by sheer volume of wood it is the biggest.
If you love statistics, pick up a sheet at any of the visitors centers  that lists the worlds’ 30 largest giant sequoias. Take the trail down the hill to visit the tree, then past it to the shuttle stop where you can catch a shuttle back up the hill to your car.