A couple spring to mind, beside A Chance In Hell, which is brilliant btw.

Down The Road I Go by Megan_Tam
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=16960&warning=NC-17Summary: A Slayer. A vampire. A 1959 DeSoto. Spike kidnaps Buffy and heads back to Brazil in a misguided attempt to appease Drusilla. What starts out as revenge turns into an experience neither will forget. If they don't kill each other first.Black Satin Voices by Eurydice
http://dark-solace.org/elysian/viewstory.php?sid=428&warning=NC-17Summary: When Willow is kidnapped by strangers with a mysterious agenda, Buffy is forced to chase after them to New Orleans, with a reluctant Spike along for the ride. Set S4-5. - CompleteI know I read more but can't recall the titles right now.