Most people believe that the devil is the father of all lies and the deals made are definitely going to put you in the worst position ever... However, if the deal is not your soul but something else:
1) Your current life for your dream life. You will get your ideal life as you had pictured. The only catch, there is no going back to your current life.
2) Your memories and your feelings for a special someone as a trade off for whatever you wish for. You get to forget and get rid of the heartaches but you lose the memories.
So... Deal? Or no deal? :)