I think anything is good in moderation.
I love balance in design, not something that looks extra or added for no apparent reason.
I like contrasting colors, preferably natural colors.
I love unique, rarely seen woods or common woods with rarely seen figure & color.
I love finesse. I love the very fine, classy, petite design aspects that are understated but bold.
I really enjoy seeing cues that leave me scratching my head, wondering how the hell the builder pulled off a certain design aspect.
I'm not crazy about wraps in general but hey, they certainly add to some cues where a wrapless handle would look out of place.
I'm not crazy about veneers in general but there are some that I simply love. It all goes back to the balance issue.
I hate gaudy designs with large design components, especially when things are too rounded or not lined up.
I hate almost all of the scrim cues, especially those with tigers or wolves. I also don't like color in scrim. To me, scrim looks best when it's fine black lines on ivory, and done to accentuate the piece rather than overpower it.
Overall, I guess I like cues where the design is tasteful, flows from end to end, and has no apparent center of focus. Again, balance.