Best musical intrument?
Percussion set. Or better known as drum set. Each piece of a set, in theory, is it's own instrument, and is used it's own way. Drums don't soley take up rhythm elements to music but they have a great deal of tone to them as well. Not many know that. With add ons such as tymponys (kettle drums) or zylophones, a drummer can achieve a full tonal scale. Also, to be a good drummer, one must learn to isolate each limb in it's own thought, as to obtain the auditory illusion of multiple instruments.
Side: Percussion Set or Drums
Cello for sure. It requires actual skill to play, unlike most percussion (drum sets and mallets exluded) and wind instruments (except oboes and maybe french horns). Skill is necessary because you have to be constantly aware of how your bowing is compared to those playing around you if you're in an orchestra, or if you're following the right bowings. Not to mention jumping between sometimes two or three strings while slurring. PLUS there's shifting constantly, so you have to be constantly on the watch for making sure you're fingers land in the right spot. And don't get me started on harmonics and thumb position!