We get the Western version of the Tiger Swallowtail here on our roses and Budlea ("Butterfly Bush") blossoms quite often this time of year. It's our biggest and to my eye, most beautiful bug of all.
We have a mimosa tree in the back yard and for much of the summer it's covered in fuzzy pink flowers that the butterflies love. Sometimes there are so many butterflies on it that the tree looks like it's alive. It also attracts hummingbirds as a bonus.