LEGO Olivia's Space Academy 41713

With relatively high brick count, this set has lots of potential for fun during assembly; but it also lots of potential for play following assembly, with 4 LEGO characters and many tools and parts that can spark the child's imagination (spinning telescope, spinning model of the solar system with Sun, earth, and moon, etc.)This set seems to be more affordable relative to other LEGO sets, since it doesn't involve any big movie or comic book brands.There are some tricky parts to assemble, so even I wouldn't go too much lower than the 8+ age rating, even if your child is precocious (I bought the set for my 4-year-old daughter, and ended up helping with a good portion of the assembly.)