I could see this girl going from cute b-lister to under appreciated non sell out who had talent as opposed to all the girls of her era who didn't
Ummm, non sellout? I mean, she had a decent career and all, but this is not Parker Posey. She did not make her name doing indie movies. Doing everything from Clueless to Just Married (which my fiance was just given as a present last week by the way), she was not some great young actress, picking and choosing only the best scripts, and shunning the mainstream. She was about as mainstream as any "B lister" could get.
Ultimately, you may be right that her legacy may shine brighter since she died at such a young age, but I don't think she is in the same category as Cobain and Ledger who died at the absolute peak of their hype. Cobain had just done the incredibly successful unplugged, and Ledger just came off Brokeback Mountain, and was already getting crazy hype for his role as the Joker before he died.
Now, if this happened right after "Girl Interrupted" or something like that, then I think that could be the case with Brittany as well, but as sad as it is, I don't think the timing quite worked out for that kind of legacy.
This is just a very sad story, and I hope the press can treat it with a little more class then they have with other celebrity stories of late, because while I don't think her legacy will grow too much, TMZ and company have the ability to really drag her through the mud if they put their mind to it.