As consumers descend upon stores everywhere for the annual Black Friday sales, let's look back at what holiday shoppers of yore bought for the little science fiction fans in their lives: 20 years' worth of Lego Space toys.

From 1978 to 1999, Lego regularly released lines of toys themed around deep space exploration. Lego Space was discontinued to make way for a decade's worth of Lego Star Wars sets, although the theme made a comeback this year with its third incarnation of the Space Police line. (You can see its flagship, the Galactic Enforcer, up at the top.) But for more than two decades, Lego continuously released more than 200 sets in its Lego Space theme, and that's what we're here to honor. Here now are some of the highlights. And yes, I'm pretty sure I've bought, built, and disassembled a good 60% of these.