Lamium looks right. I think I've seen the spotting/pattern on Lamium galeobdolon 'Herman's Pride' get less defined like that in really shady conditions so that could be a possibility (but I won't swear to that memory!
) If so, then it would have yellow flowers. If it's a Lamium maculatum cultivar then it will have some shade of pink or white, but the leaf shape doesn't look quite right to me. I wouldn't bet $ on it, but I'm leaning toward Lamium galeobdolon for an ID, though.
Edit: Oops, cross-posted with Lori. I bow to her seemingly perfect plant identification skills!