Dylan

According to the article about Dylan Thomas on Wikipedia as of today, his father chose the name Dylan. Both of his parents were fluent in Welsh and knew that the correct pronunciation in Welsh was more like English "dull" than "dill". However, his mother objected to that pronunciation being used when English was being spoken because she didn't like his name sounding like "dull one". So Dylan Thomas himself pronounced his name with "Dill" in the first syllable when he was speaking English.

Note that the original Welsh pronunciation of the name would rhyme more closely with "dull-in" than "dill" (as in dill pickles), even so I honestly think that the "dill" pronunciation is much more acceptable in the United States. I'm sure a reference to pickles as opposed to being a dull person is much easier to deal with!

Pronounced "DUHL-EN".

As a Welsh speaker, I advise it should ALWAYS be pronounced "Dul- an", as the letter "y" in the first syllable of a Welsh name is generally pronounced this way, with subsequent syllables containing "y" being said as an EE or I sound. It infuriates me when people get it wrong - it is disrespectful to the Welsh language and the origins of the word.

Pronounced DIL-an.