Any of the Mountain Boys. I keep thinking that one day I will find one at a charity shop or bootsale, so far I only have Fireball and Tornado (lucky eBay wins) as I don't want to spend an arm and a leg on one.
I have a recurring dream though where I find a box of dirty-looking ponies at a bootsale. The seller wants a tenner, and there are small children poking about in it so I buy the lot unseen. Take the box to the car and find piggy ponies, loads of Spanish ponies and Ladybird...in my dream I am sat there pinching myself and my OH asks me "why are you doing that?" I say it's to make sure I'm not dreaming. Then, at the bottom of the box, is a beautiful pink and purple swirly pony that I have never seen before. I then realise in my dream that I am actually dreaming and wake up in a strop