first dark souls for ps4

i wanna buy one, i heard the 2 is the best one and the 3rd is the most difficult. Is this true? i was thinking about getting the 2. What would you recommend me? i dont think ill buy another after this one (maybe yes idk) so i want the best of the best as my first. im literally in front of my psn so help me asap plssss thanks in advance !!