I will sell bitcoinbank.com if anybody is interested.
I'd only be interested in bitcoin-bank.com
Registered bitcoins-bank.com and a couple of others, also planning on actually opening a bank there.
You should only use hifens on domain names when they are really needed or the domain without the hifen is gone.
You would be surprised on the number of visitors who won't remember the hifen, altho it makes it easier to read the domain.