Are you more impressed by a really good singing ability or the ability to play an instrument?

More impressed by playing an instrument well. With singing, for anyone with a good voice, half the work is done already---all that's needed is training. With an instrument, however, since no one is born knowing how to play, you start from scratch.

I sing, and I sing well, and I agree with you. While you may have a natural inclination for understanding music, you're not born with the ability to play an instrument. Anyone can be a good guitar/piano/etc. player if they're dedicated enough. Singing, on the other hand, is something you have to have at least a small amount of natural talent for. If you're horrible, no amount of teaching is going to fix that.

Basically, a good singer is partially lucky. A good instrumentalist is simply skilled.

I am more impressed with someone who can play an instrument. All of my reasons have already been elaborated in the other answers. lol

Both. I consider the voice to be a musical instrument also. There are and have been many excellent proffessional pianists who cannot read music. Some say they are gifted also.

Both they both take talent, and also for me if your voice or instrumental abilitys touch my soul or emotions and really make feel something I like it and that's talent to me. . . But it just depends

by a personality.