If I hadn't already read the entire series, and if I was judging this book just by its own merits, I'd still be saying that it harnesses the lightning and even finds a way to make it go side to side rather than up and down. 
 It's really fantastic as a straight fantasy with tons of humorous elements, with a good deal more worldbuilding than all the later books, more obvious and harsher tongue-in-cheek elements, and a great setup for the Great Wizzard Rincewind. 
 Honestly? I love Rincewind. I love the shard of the Great magical spell lodged in his brain, Death's endless chase for him, the straight adventure he finds himself in, and the sheer fact that HE SURVIVES. 
 Twoflower is awesome, too, and the chest is one of the greatest unsung heroes of the age, and there is a very good case to be made that this whole novel (and the one following it) is probably the BEST INSURANCE MAN'S TOURIST GUIDE EVER WRITTEN. :) 
 'Nuff said. 
 Am I sad that Sir Terry is no longer with us? Yeah.