Which is the best Bass instrument?

Double Bass

It has great, unmatched, flexibility - from the classical Orchestra to Jazz - it can be bowed or plucked - and has the ability to blend smoothly with other instruments while providing the bedrock of the overall sound. But this blending also means that it cannot articulate clearly - the sound is too fuzzy for that. Hopeless for solo work.



Bassoon

Great articulation - and when a bassoon is added to the double bass section the combination is able to reveal the 'corners' in (for example) the basso continuo part of baroque era music. Also makes a very good solo instrument, with a wide range of tonalities. But, on its own, the sound lacks the fullness of the double bass; and the good articulation comes at the price of rather poor blending ability. Also, the bassoon is intrinsically funny - somehow it cannot do tragedy.



Tuba

A strong, round, loud sound - and has the ability to do both smooth legato and to bounce-along as support for marching music and the like. Blends seamlessly with other brass instruments. But draws too much attention to itself when playing with strings and woodwinds - and in small groups tends to make the music sound samey.



Bass Guitar

Not much use for anything 'classical' outside of the pop/ jazz/ folk realm but marvellous and essential in that realm - great for rhythm, and has unexploited potential for supporting church and communal singing.



Bass Saxophone

Big, fat, powerful, well-articulated sound - but even more dominating than a tuba; and I must admit it is really a novelty instrument! When the bass sax is going, its hard to listen to anything else - but it can do terrific jazz solos!


https://www.youtube.com/watch?v=ZxP0cf1bpTM



The bass saxophone contrasted with the double bass shows that there is no best bass instrument overall - if you can do blending and sweetness, then you can't do articulation or make a good solo instrument; because a strength is also a weakness.

It's a case of horses for courses.