Plain wicker/straw baskets are great fun for bunnies, they are cheap too.
I usually fill full of straw for a litter box, then when its chewed down to nothing, whatever is left can go straight into the compost piles.
All my rabbits love their pinecones . . .
They chew em up, flip em around, generally play with em.
I have only ever used dry brown ones, but I think next time Im in the mtns Ill find some closed green ones.
On average, the pinecones last about a week with my rabbits, I have almost a entire pick-up truck load of them.
Even a big, old, mature new zealand doe I got has started playing with the pinecones, hers is nibbled almost down to the core, does a pinecone have a core?
I also give them chunks of apple wood to chew, and they nibble all the bark off then play with the rest for a few days till I replace.
Sometimes I hang the peices from a shiny chain, this makes it even more interesting to them and a bit more of a challenge to "use".
One other thing I have done to help alleviate "boredom" in my rabbits is to raise their feed bowls and hay racks so they actually have to stand up/"work" to eat, really helps with the laziness if they cant just lay in one spot and eat all day.
I finally got the guy from craigslist to come over today, Im trading him an older 6hp outboard and a older elec trolling motor for 4x 200' rolls of 1"x2" rabbit wire and 10lbs of j-clips, I got the motors for free years ago and in my opinion, Im getting over . . . each roll sells for almost $300 new
With these rolls, I can make all kindsa pens and runs for my bunnies, my plan is to have each hutch have its own "yard", and a couple bigger ones for group playdates.
6 of my males are now fixed(1 is not), and I have 15 total bunnies.