In reply to Sean Kelly:
Safest for a Brit is to say Van (rhymes with one) Gog (rhymes with cog). Similarly Gullit is beter than Hullit.
You have Ronald Koeman (Dutch footballer, national coach) and Nellie Cooman (Dutch sprinter) always made me laugh that British commentators pronounced them the opposite of how it is in Dutch. They could clearly pronounce the names, just the wrong way round.