Is it "el" or "los" EE UU?
Does "el" or "los" precede "EEUU"? It seems that it should be "los" since 'EEUU' stands for 'Estados Unidos', but then again, 'el' sounds a lot better.
Also, in conversation to you say "E-E-U-U" or do you say "E-U" or just "Estados Unidos"?
In Spain, the normal is "Estados Unidos" and "los" precede "EEUU".
"Estados Unidos" is, of course, plural and, as such, takes a the plural form of the definite article. We have a (somewhat intrusive and not very sophisticated) filter which attempts to prevent "shouting" (the internet convention being that when one writes entirely in upper-case, one is "shouting"). The filter is badly written and unable to distinguish between "words written in upper-case" and [standard] abbreviations. It is unlikely that the filter will ever be fixed.