by far, far and away, easily [adverb]

"Verreweg" is composed of "ver" ("far") and "weg" ("way/road"). The additional "re" in the middle is basically glue, but comes natural to the Dutch speaker. Mind that without the "re" it would sound as "ver weg" which means "far away".

Examples:
-"Pieter van den Hoogenband is verreweg de meest succesvolle Nederlandse zwemmer."
("Pieter van den Hoogenband is easily the most successful Dutch swimmer." Read more about Pieter in the Extra below.)

– "Bea is verreweg het aardigste meisje dat je in de trein van Den Haag naar Amsterdam kan ontmoeten."
("Bea is by far / far and away the nicest girl who one can meet on the train from The Hague to Amsterdam.")

– "Ik was vroeger goed in alle vakken op school, maar ik vond wiskunde verreweg het leukste vak."
("I used to be proficient in all subjects at school, but mathematics was by far my favourite subject.")

Extra:

Other than being very successful, Pieter van den Hoogenband is also a very popular sportsman. In fact he has almost become a BN’er (Bekende Nederlander) by now. Pieter van den Hoogenband officially retired from professional swimming after the Beijing Olympics where he was not as successful as he and the entire Dutch population had hoped.
He was world record holder on the 100m freestyle for 8 years, a record set in Sydney 2000. In the past 6 months this record was broken 12 times, attributed to the recent advances in swimming attire of which the more force-driven swimmers seem to take most advantage. Pieter van den Hoogenband however was never renowned for his strength, but more for his technique.

Reason for Pieter’s popularity outside the swimming pool is his genuine friendliness and down to earth, modest, mentality. A typical Pieter van den Hoogenband performance in this context is his reaction to his friend Maarten van der Weijden winning the 10km open water race during Beijing 2008. Check out this video of the last meters of Maarten’s winning race (first wait for the commercial to end). You will hear Pieter – a commentator during the race – screaming euphorically and then after the race you will see him hugging Maarten. The fragment is taken from yesterday’s talkshow "Holland Sport". If you are bored and your Dutch is good enough you can keep watching the show which is all about Pieter van den Hoogenband and Maarten van der Weijden. Another interesting note is the fact that Maarten van der Weijden recovered from leukaemia in 2001 and managed to return to professional swimming.