Ok this is a hard one.
X-wing the first rebel fighter we saw and it was in the attack on the first death star, it can make a sound, open wings and a little red button will make some laser light.
The Rebel Armored Snowspeeder Vehicle, there is room for 2 pilots, it has the catapult and there is sound and a huge lightshow on both guns which is a little bit better than the x-wing for me. So I have to choose the Rebel Armored Snowspeeder Vehicle, but damn it is difficult