I have great memories of my friend Steph and I painting an underwater scene on one wall, writing ridiculous things on my "graffiti wall" and a giant Barney the dinosaur poster on one of my collage walls. It was a ridiculous bedroom but I loved being allowed the freedom to express myself in whatever way I wanted. I think my friends may have been a little jealous as they went to bed in their fairly proper rooms.
So with out further adieu...here is my room circa 1994.
Things to note: The mermaid with huge boobs, the odd little door that lead to my cubby hole(one of the best parts of my room), my toddler rocking chair and creepy porcelain doll.
Things to note: Cow spotted pillow case, foot prints on the wall, the proclamations of love that are crossed out and awesome sayings like "Madder than a hippo with a hernia"...dear lord...how embarrassing!
Things to note: Many little hand painted crafts, little hand stitched dolls and books. All things I love to this day!
Things to note: The most disgustingly ugly carpet in the history of carpet, the Barney poster stolen from my then toddler brother and royal blue bean bag chair.By the time I was 17 I decided that I was too mature for all this and painted over it all with a buttercup yellow (word of warning, don't write on your walls with sharpies, it is a bitch to paint over and takes like 6 coats to cover it) and got a white and floral duvet and matching curtains....so my bedroom was back to boring but also a good representation of me. You will still find elements of both these rooms in my current house, both the chaotic and subdued and I think it works quite nicely!
You should definately check out the Teenage Bedroom site. It is fascinating. As creepy as it sounds I could spend hours looking into the bedrooms of teenage girls(which isn't creepy because I used to be one, right?).