I think the words we choose to describe everything are mainly bearing extralinguistic information. In spanish is really easy to see the double sense of many words, and not only the "secret message" but the abstract sense, the visceral sense. The sound, the construction of the phrase, the way that we articulate a sentence, says more by its construction that by its meaning. Not only in poetry but in any non technical text.
For me is really hard to tell you my favorites words, since it's conections can made a simple word something espectacular . You can take a few of usual words and make a sophisticated sentence:

This is a Cesar Vallejo's Poem, i think is amazing so let my put it.

Epístola a los transeúntes ////// Epistle To The Transients

Reanudo mi día de conejo ///// I resume my day of a rabbit
mi noche de elefante en descanso. ///// my night of an elephant in repose.

Y, entre mi, digo: //// And, to myself, I say:

ésta es mi immensidad en bruto, a cántaros, //// this is my immensity in the raw, in jugfuls,

éste mi grato peso, que me buscara abajo para pájaro: //// this is my graceful weight, that sought me below to become a bird;

éste es mi brazo //// this is my arm

que por su cuenta rehusó ser ala, //// that on its own refused to be a wing,

éstas son mis sagradas escrituras, //// these are my scriptures,

éstos mis alarmados compañones. //// these my alarmed cullions.

Lúgubre isla me alumbrará continental, //// A lugubrious island will illuminate me continental,

mientras el capitolio se apoye en mi intimo derrumbe //// while the capitol leans on my intimate collapse

y la asamblea en lanzas clausure mi desfile //// and the lance-filled assembly adjourns my parade.

Pero cuando yo muera //// But when I die

de vida y no de tiempo, //// from life and not from time,

cuando lleguen a dos mis dos maletas, //// when my two suitcases become two,

éste ha de ser mi estómago en que cupo mi lámpara en pedazos, //// this will be my stomach in which my lamp fit in pieces,

ésta aquella cabeza que expió los tormentos del circulo en mis pasos, //// this that head that atoned for the torments of the circle in my steps,

éstos esos gusanos que el corazón contó oir unidades, //// these those worms that my heart counted one by one,

éste ha de ser mi cuerpo solidario //// this will be my solidary body

por el que vela el alma individual; éste ha de ser //// over which the individual soul is watching: this will be

mi hombligo en que maté mis piojos natos, //// my navel in which I killed my innate lice,

ésta mi cosa cosa, mi cosa tremebunda. //// this my thing thing, my dreadful thing.

En tanto, convulsiva, ásperamente //// Meanwhile, convulsively, harshly,

convalence mi freno, //// my bit convalesces,

sufriendo como sufro del lenguaje directo del león: //// suffering like I suffer the direct language of the lion:

y, puesto que he existido entre dos potestades de ladrillo, //// and, because I have existed between two brick potentates,

convalezco yo mismo, sonriendo de mis labios. //// I too convalesce, smiling at my lips.

*Translated by Clayton Eshleman, Jose Rubia Burcia
*Hombligo is without H. Ombligo means nave. The original poems bear H.