Topic: Sweet, fly, and solid:
...the approving sweet has a certain currency among today’s young users of slang. In fact, it’s been popular for decades. But sweet had its first known heyday in the 1930s and 40s, before disappearing from the slang horizon for a generation.
Similarly, fly, meaning "well-dressed," first came to prominence not during the musical rap scene of the 1980s, but hundreds of years earlier. 19th century thieves’ cant used fly to mean "smart; cunning." It reappeared among early 20th century jazz musicians with its same positive connotation, then orbited in and out of the lexicon for the rest of the century.
Finally, there’s solid, one more term of praise. Solid was around in the forties, then melted away before re-forming into slang of the 1960s.