Ever heard of the Mary-Sue concept? I hadn't. Not until I started doing some research about what makes a heroine likeable. Wikipedia have a detailed explanation of what a Mary-Sue is which you can read here. But this quote just about sums it all up:
"A Mary-Sue....is a fictional character with overly idealised and hackneyed
mannerisms, lacking noteworthy flaws, and primarily functioning as a
wish-fulfilment fantasy for the author or reader."
I stumbled upon a Mary-Sue litmus test (apparently there are a few different versions) and in my usual 'what-the-hell' way I took the test. Luckily my heroine escaped the dreaded label. However, after more research I found that the term has been bandied around by a lot of critics and it has been suggested that its very existance may have stopped some writers from writing out of the (real or otherwise) fear that they had created 'just another' Mary-Sue character.
So go on, take the test. You can do the Univerisal Mary-Sue Litmus Test or the Original Fiction Mary-Sue Litmus Test. You can use it to test one of your characters or someone else's or even yourself. One test claims Bono from U2 is a Mary-Sue. ? Go figure.
Apparently Bella Swan from the Twilight series is currently holding the title of Queen Mary-Sue but what about other Mary-Sues (Lara Croft from Tomb Raider comes to mind, Elizabeth Swann from Pirates of the Caribbean, Ginny Weasley from Harry Potter transforms into a Mary-Sue and James Bond would have to be the Emperor of Gary-Stus - the male equivalent of a Mary-Sue).
Just remember there is a lot of discussion about what makes a Mary-Sue and the test being flawed. The main gist of it is that your female protagonist can't be better than perfect or you run the risk of alienating the reader. We have to be able to relate to the protagonist and who amongst us can claim perfection?
Aside from Mr Clooney, of course!