Wooden beads are fun to work with. They are fairly cheap, and come in lots of bright painted colours. For the less adventurous, there are plenty of natural varnished beads too.
Wood is very light weight, so you can do chunky without heavy. It's great for summer jewellery because it is cool to wear. Glass can feel hot and sweaty when (or if!) the sun shines.
Wooden jewellery tends to be a bit rustic in character. However, it associates well with metal beads, which can up the elegance factor. It's also very suitable for younger folk.