I've read a lot of Terry Pratchett's stuff, probably from when I was, like, 14.
Terry Pratchett's right up my alley ... give him a try!
I consider science fiction and fantasy my genre. And I've noticed over the years that there doesn't tend to be a lot of lighthearted, comedic stuff.
I don't choose something unless I think I have a personal understanding and something I can offer. It's not always thematic. I wanted to do 'The Grinch' because I wanted to direct Jim Carrey creating that kind of comic fantasy character live. I just thought that would be a mind-blowing experience, and it creatively was.
'Discworld' is taking something that you know is ridiculous and treating it as if it is serious, to see if something interesting happens when you do so.
Sir Terry Pratchett - he was knighted in 2009, and on him it looked earned rather than entitled - wrote about dragons, wizards, turtles, witches, time-travelling monks, and suitcases with legs.
I think when people mean that Discworld books have become darker they really mean the series is growing up. In 'The Colour of Magic' most of the city is set alight. It's a joke, in much the same way that the Earth is destroyed almost at the start of Douglas Adams's 'The Hitchhikers Guide to the Galaxy.'
Douglas Adams' Hitchhiker series also shows the potential of lighter fantastic fiction. I read the first, and listened to a tape of a later one, and it's fun.