Things or places starting with "X" are rather rare. I can only think of X-ray, Xenia, and xylophone.
Even if x-rays are important as diagnostic tools, I cannot say that I like them. Xenia is a flower that looks like mums. Since I love almost all kinds of flowers, there is really nothing about Xenia that I can pinpoint as something I specifically like. So I am settling for xylophone.
What I like about xylophones is their sound. It is very refreshing and inviting. Every time I hear their sound, I am always reminded of either bells or the gurgling sound of a brook. I love it especially if I hear the sound early in the morning. I feel that a bright and lovely day is unfolding if I hear the sound.