tuco. who else ???

[KERMIT]

as usual.  no revelations from me.   just this observation.  tuco is sitting on the horse, waiting to be hung yet again   .   the devil waiting to bite his ass.        just  before he is  to be executed, as far as the gawking townsfolk know,  he's getting so board by this time he let's out a ugly sneer to a old fat lady who smartmouth's him causing her to shrink back in disgust.  
beyond cool my freind,
       

[Blueberry]

Another great Tuco moment:

When Blondie collapses in the desert and Tuco, in an extremely casual way, lets the water bottle roll down the hill side, hitting Blondie right in the face - from quite a distance... What powers of calculation - in that moment Tuco really feels superior and that kind of self confidence is exactly what enables him to perform a super hero stunt like that.

This must be the peak moment for Tuco in the movie - also consider the way the scene is shot - with Tuco ridin´ high above Blondie, who is just miserable. Well, this movie has its ups and downs for both...

[CalamityJane]

In those scenes you described and in others, I think that Blondie knows that Tuco is pretty slick and coy, but he also knows that he's a better shot than Tuco.  It seems to me that Blondie lets Tuco think he's sly and sneaky 'cause Blondie knows he's got the edge when it comes to the draw of a gun.