There are a lot of exchanges allowing fiat withdraw, it just depends on what kind of documents you are ready or not to provide to verify your account. And also another point to consider is your location. For example, as a US citizen, I think Coinbase is the most convenient, a European would prefer Kraken as it's cheap. Here are a few I know about.

Coinbase https://www.coinbase.com/
GDAX https://www.gdax.com/
Bity https://bity.com/
Safello https://safello.com/ SEPA
Kraken https://www.kraken.com/ SEPA and Bank Wire Withdrawal
LiteBit https://www.litebit.eu/ SEPA
Cex.io https://cex.io/ you can sell Bitcoins for USD, EUR or RUB Withdrawals to payment cards, Bank transfer and SEPA
BitPanda https://www.bitpanda.com/ SEPA (It's not an exchange but I think it's good to mention it)
Bitstamp https://www.bitstamp.net/ SEPA and International withdrawals

Kraken, BitStamp, BTC-E
By fiat do you mean just SEPA or international wire, or also other payment methods transacting in USD or EUR?

Can you just clarify something... are you wanting to send money to another person? or are you trying to transfer money that you hold in Vietnam and have it end up in your own US Bank Account?