There are many, many varieties of Crape Myrtle. Below is a very short list of some of my favorites.
Acoma - A semi-dwarf with a weeping habit that grows to about 10' tall with an equal spread. Can be tree-formed or left to grow naturally into a large mound that becomes covered in white flowers during the summer. The dark green foliage turns shades of red and orange in fall. Excellent mildew resistance.
Natchez - Features large, white flower clusters for up to 100 days during summer! Grows 25' tall with a spread up to 20'. Has a broad, weeping canopy. The large, oblong, dark green leaves turn to red and orange in fall and contrast nicely with the cinnamon-colored, exfoliating bark. A great choice where a larger tree is desired. Excellent mildew resistance.
Muskogee - Features large, light lavender flower clusters for up to 100 days during Summer! Upright habit to 25' tall and up to 20' wide with a broad, weeping canopy. The large, oblong, dark green leaves turn to red and orange in fall and contrast nicely with the tan to gray bark. A great choice where a larger tree is desired. Excellent mildew resistance.
Tuscarora - Features large, deep pink (watermelon-color) flower clusters for up to 100 days during summer! Upright habit to 16-20' tall with a broad canopy to 12-16' wide. The large, dark green leaves turn to red and orange in fall and contrast nicely with the tan bark. A great choice where a larger tree is desired. Excellent mildew resistance.
Tonto - A semi-dwarf that features an abundance of large, deep pink (watermelon-red) flower clusters for up to 100 days during summer! An upright growth habit to 10' tall with a broad rounded canopy to 8' wide. The dark green leaves turn to deep maroon in fall and contrast nicely with the light tan bark.
Sioux - Features an abundance of large, intense pink flower clusters for up to 100 days during summer! An upright habit from 10-16' tall with a broad, rounded canopy 8-12' wide. The dark green leaves turn to deep purple and red in fall and contrast nicely with the light tan bark. A great selection where a mid-size tree is desired. Excellent mildew resistance.
Catawba - Features an abundance of large, purple flower clusters for up to 100 days during summer! An upright habit from 12-20' tall with a broad, rounded canopy 8-12' wide. The dark green leaves turn to burgundy and red in fall and contrast nicely with the exfoliating tan bark. A great selection where a mid-size tree is desired. Excellent mildew resistance.
Dynamite - One of my personal favorites. Features an abundance of large, true-red flower clusters for up to 100 days during summer! An upright habit from 12-20' tall with a broad, rounded canopy 8-16' wide. The dark green leaves turn to orange and red in fall and contrast nicely with the light tan bark. A great selection where a mid-size tree is desired. Excellent mildew resistance.
You can buy Crape Myrtle trees at GardenerDirect.com