Paradise Lost

Is it worth reading? The story itself seems interesting, but I'm not sure if I'd be able to tolerate the way in which it's written.

Same question for Dante's Inferno.

Dante's Inferno is worth reading but you have to find a guide to go along with it (no pun intended) because it's a social commentary on Dante's society and many of the people and punishments included in it were meant as mockeries of local celebrities/politicians etc.

If you read it as a straight trip through hell, you'll entirely miss the point but you'll probably be fairly entertained.

As for Paradise Lost, I've never finished it but I happen to like the way it's written. I suppose it's also probably worth reading at least once.

I also enjoy both and recommend a guide for atleast the Inferno.

For Inferno, get the Allen Mandelbaum translation.  It's awesomesauce, and has the guide.  And it has cool pictures, too.

fgj