I like a grid that has an overall theme running through it.

Colourful

Solvable very quickly once I got the idea, and it's a nice theme, but 'all linked with ----' is too vague for my taste, especially when two or three things in a group might be words that follow the link term and one or two are things that are loosely something to do with it. It leaves the groups feeling a bit vague and arbitrary to me. For example,
I don't think happiness is associated with yellow, so don't see how fits in at all.