Bartleby
Bartleby.com: Bulfinch's Mythology: The Age of Fable
Bulfinch's collection of Greek and Roman myths is available here in full text format. A little known feature of this work is its sections on Eastern mythology, Northern mythology and a section on Druid religion.
Other
Greek Mythology Today and Myth of the Month
A large Greek mythology site focused on students and expressing a great love of Greek myth. Contains the Myth of the Month, as well as Homework Help concerning myths. Humorous and colorful.