I think that the Ambulance Ltd. Cd is great for makeouts. Expecially "Ophelia" and their version of Velvet Underground's "Ocean" (tres bien cover). Also, Belle and Sebastian's "Sleep The Clock Around" is the all time greatest song for early morning and late night kisses.
Also, Roxy Music is goodish. Don't ask me why.
For seduction's sake, I don't know why, but Tom Waits' "Heart Attack And Vine" and sometimes stuff like "Eggs And Sausage" or "Burma Shave".
Also, me and my jazz-friends voted Herbie Hancock's "Chameleon" (15 minutes of pure funk-gasm) as the best porn groove / sex song ever.