hmmm... that's such a generalized question. There's a lot of small transforming VF-1's. If your looking for something very accurate and small, then the 1/100 line would be your best bet. But if you don't care and just want something small that transforms then the K&M valks would be ok even though you have to swap parts out to transform it. There's also the takatoku version of the toy that sh002 posted. The transformation on that toy is rudimentary and it's all plastic. Now if you want the super deformed look, then the smallest you got are the takatoku and toynami morphers. Those transform, but are pretty crappy. Joke Machines are the most accurate transforming SD type toy you'll ever find out there. It transforms close, if not exactly to it's bigger brother, the 1/55 scale valks. In fact, I'd say it's transformation is more close to the 1/100 scale valks.