My favorite words to say in various languages:  Esperanto:  insekoj, Portuguese:  liquidificador, German:  Flammenwerfer.  I'm not sure I have a favorite Spanish or English word.  Maybe the longest one for English:  antidisestablishmentarianism.  I'll have to think about Spanish.
@hobbsc my favorite english word is 'widdershins'
@jezra you kiss your mother with that mouth?
@jezra i'm adding that one to my vocabulary, thanks.  really going to confuse my son.
@jezra great word! I forget if it means "clockwise" or "anti-clockwise", though. IIRC there's a related word "deosil".
@ericxdu23 deosil relates to the path of the Sun and will result in a sun dial moving clockwise.