I like
Merry as a nickname more than as a full name, but I think it'd work. It sounds a bit too cutesy by itself--it has none of
Mary's weight, even though I pronunce them the same way--to be taken seriously.
Merry Anwen sounds like a description to me, rather than a name. I think it'd be a great nickname for
Meredith (which I otherwise detest),
Mercia,
Merletta,
Meriel /
Mariel, Merridy (blame chazda), or
Meryl.
I like
Merry just a little bit better for a boy--as a nickname, of course. (Since I really don't like Lord of the Rings, I wouldn't dare saddle a son with a full name so resonant with it.) On a boy, I like
Merrick,
Merit,
Merle, and probably some others that I can't remember.
Array
"What are these parents thinking?...Let's name her Madison--she'll live in her own world: 16 square miles surrounded by reality." -- Susan Lampert Smith