Oh, thats easy...YELLOWSTONE!I love winter time in Yellowstone the most. Summer is too crowded, winter, you get to see the animals up close, except the bears, spring and fall are best for bears.
Yellowstone: it is much larger, has much more variety, and the ability to view wildlife in their natural habitat is second to none. In addition, winter access and variety of attractions is phenomenally amazing.Even during its most crowded times, it s possible to drive or hike a mile or two and be completely alone, yet in beautiful and scenic surroundings. In Yosemite it requires a bit more work to get away from the massive crowds.
Yosemite.Simply more beautiful than Yellowstone.