Wilhelm

This name is very old and hardly used in todays Germany.
Germans usually connect their great grandfathers with this name as it was popular in the 1800s and early 1900s and to native german ears this name sounds literally as if you would "want a helmet"! I think it's not nicer than William at all, especially because the name William is still used regularly. I would really not consider it for a child and if at all only to honour an ancestor and only as a second name.

This name is also found in the Anglo-Saxon Royal Genealogies. Wilhelm was the third great grandfather of Redwald, an East Anglian king, who is believed to be the subject of the Sutton Hoo ship burial. The name Wilhelm was eventually replaced in England by the Normam form 'William'.