Huobi depth is wrong since it only shows a small range.
Bitfenix depth is wrong because it can be faked
BTC-China depth is almost static, but has dropped about 20% in asks and 40% in bids in a month
BTC-E depth is too small (and not rising) to matter
Other chinese exchanges -
Eur exchanges - way too small to matter
So in the end, Bitstamp speaks for all exchanges when it comes to visible bid/ask depth.