Alice Neel (Neel didn't lack the courage to represent herself aging)
Van Gogh (his many self portraits are well-known)
Rembrandt painted ones of the most fascinating self-portraits in the history of art. See more of Rembrandt self-portraits here: http://www.rembrandtpainting.net/complete_catalogue/start_self_portraits.htm
Catherina van Hemessen
There are many other self portraits out there. Make your own research and pick up which ones you like or don't like, and find out what exactly you like or don't like at them. Prepare for your own self-portrait. As you can see there is a variety of styles and techniques, chromatics and compositons to try.
This is my own self-portrait, a combination of photography, pastel drawing and painting. This self-portrait was a compulsory theme for one of my exams at the Art School. The light is natural, and it comes from a terrace on the left side, no photoshoping was involved. The self-portrait had to represent me as a free and independent individual and as an artist.