I prefer TBPs - they take up half the space that hardcovers take up - and the dustcovers on hardcovers get really tatty if you're not careful.
I honestly don't think there's a big difference in how durable they are unless you're talking about the posh hardcovers with cloth spines.
David Brin: Life Eaters.
“Faith in faith' he answered himself. 'It isn't necessary to have something to believe in. It's only necessary to believe that somewhere there's something worthy of belief”
― Alfred Bester
Not dark, per se, but Locke and Key is a GREAT series. Very trippy. I think they have 5 or 6 TPB volumes out now. I'm about 23 issues in right now. It's basically an homage to Lovecraft's work. Not really based on anything he's done, but there are several nods to him throughout the series.
I just finished the adaptation of House on the Borderlands by Richard Corben and it was dark and fantastic.