I might have spent the whole afternoon viewing the European Collection, but the Shakespeare Garden called out to me pretty strongly. The blooming flowers were wonderful, especially after a stint in the Midwest over Christmas. It's incredible to think that part of the country is under snow and ice while California.... Well, that's why it's crowded out here!
Then, given the time of day (sun/shade), I had to rush to the Japanese Garden. Whether you want to enjoy the views of the bridge, the bonzai trees, or the Zen-like rock garden, the Huntington has everything you need to imagine the finest in Japanese gardening.
On a sunny winter's day, you can't do better anywhere.