All cats have their own characteristics. Personally I think they are a little too proud and dignified to show happiness in an unrestrained way! When content, many cats, mine included, purr and almost close their eyes or do long, lazy blinks with their eyes. I remember one day my younger cat was playing and running along happily and did a sort of skip with her back legs, a bit like a rabbit does! There are lots of books around that tell you how to "read" your cat by looking at the way she holds her tail or her ears etc. Also how to learn to interpret the different little sounds they make, like a chirrup when they enter a room, to announce themselves, and the different miaow sounds. It'll be interesting to see what our other forum friends have to say on this.