Breathless
Part of speech: adjective
Definition: Having difficulty breathing; gasping. That makes one hold one's breath (with excitement etc.). Not breathing; apparently dead. Having no wind; still, calm or airless.
Example sentence: I was wanting something new, and for me the Beatles were... outstanding. I was breathless, speechless.
Breathtaking
Part of speech: adjective
Definition: stunningly beautiful; amazingVery surprising or shocking; to such a degree as to cause astonishment.
Example sentence: Everyone should walk across the Brooklyn Bridge. I did it three days in a row because it was one of the most exhilarating experiences I've ever had. The view is breathtaking.