Thunderbird 2.
1. It's fantastically impossible. I love things that are clearly impossible as they challenge you to suspend you disbelief
2. Clearly for throwing at a sibling, it's the best. You know full well that the Thunderbird 1 and 3 models* had rubber noses, so they never hurt. Thunderbird 2 was more like a brick and likely to cause unconsciousness/death.
3. It was like the Earth Mother Goddess of Thunderbirds. Big, fat, green and gave birth to wonderful mutant little Thunderbird babies from its belly.
* I had them, they did - but not the original 1960's releases, but you wouldn't be chucking them around as they'd be worth too much.