Perhaps the antics of the Chickadee or Titmouse earn your vote. A lot of folks like Penguins. Birders appreciate birds with beautiful, musical voices. The Wood Thrush is a favorite of many. The other members of the Thrush family are very good singers as well.
Some folks love seabirds.
You need to take an all-day trip out into the ocean to see them. The Wood Warblers of North America are small, colorful birds. The Blackburnian Warbler is one of my favorite birds. One perched 15 feet in front of me in the bright sunlight on my first birding trip. After a trip to Central or South America, it is very likely that the Tanagers might become your favorite birds.