Possibly the most important piece of advice I was given when emigrating was that the high street banks were not the best people to entrust with your money transfer overseas. How do you know that the bank teller has any idea what you are talking about (not being belittling but it probably isn't an everyday service)? They charge commissions, transfer fees and then to cap it all off they give a reduced exchange rate.
Essentially, the high street money transfer agencies are similar to the banks. They may know more about the transactions but will hit you with commissions, charges and not the best rates.
Travellers cheques and cash speak for themselves don't do it! They are easily lost/stolen, some countries only allow a limited amount of cash to be carried into the country and in the case of travelers cheques, you may have to pay to buy them and then to cash them in. Just plain don't do it!!!!
Last, but not least, it's the international currency transfer companies. I had no idea that international currency transfer specialists even existed, never mind the exceptional services on offer.