As a kid I had a box full of just various blocks, but I had a couple of space themed kits... I put them together per the book, messed with them a little, and then they got taken apart and just mixed in with the other "regular" Legos. Lots of opportunity for creativity there.

2-M60s, VP180, 8-M3s, SVS 20-39PCi, DIY Sub, 8-Shakers, JVC RS45, Anthem MRX-1120