All my dwarfs have enjoyed different things.
Felix can't live without his pink elephant jungle bungalow which he sleeps in, eats in and just sits in and watches the world go by. If I don't put it in his cage he looks very sad. He also has a hide and see TV thing that he loves to sit and wash in
Felix also likes his grassy hay tunnel from P@H which he chews and sits in
When Patrick and Sponge were here they each had a bendy fiddle sticks shaped into a cave type thing and they loved them, they slept under them, ran on top of them and just sat under them and ate when they were using a different bed.