Certain words enchant me --- and a common thread seems to be that although they appear to break the rules, in reality they obey other more subtle rules. I enjoy nouns that take slightly exotic plurals, like automata, fungi, kibbutzim, staves, and indices. Also captivating are clusters of words that seem to be a unit until they have to be pluralized: courts martial, sisters-in-law, etc. And then there are the endings --- e.g., "-esque" as applied to words like "Beatles" or "Rubens" --- which almost universally are misused. The joy comes from getting it right.
Making up attractive new words is an entertaining game that likewise brings together language and æsthetics. I particularly groove on coined terms that hint at multiple meanings, that allude to little-known arcana, and that resonate with other fun linguistic elements. Recently Amanda Williams of http://www.metamanda.com/ issued a challenge: come up with a name for her new computer.
My latest suggestion: "metanomie". It doesn't mean anything (I thought of it on the way home from a long run earlier today --- probably my brain was oxygen-starved again) but it does contain:
Now if I could only work a letter z in there someplace ...