Language doesn't matter, although you might want to add a translation or definition to unusual and/or non-english words. Meaning doesn't have to matter, but it can.
Just post your words.
I find this word synaesthetically pleasing... It gives my brain a tingling feeling and I see colours.
Finnish for brain(s). And just now I realized how many brain-related favourite words I have. I just like the way they sound. I have a special thing for the diphtong "ai".
More of these. This is warm and runs all over my skin. I like it better written than spoken, but both are wonderful anyway.