my advice is to keep achtung baby for last
Why? Because with the four albums that you have by now, you probably have realized already that we are talking about the best band ever. Then you still have room to appreciate atyclb, htdaab and rattle and hum. Then you still have room to be delighted with war, zooropa and the unforgettable fire. And finally after that you will witness what you think that is impossible – to listen to an album that surpasses all of the work previously mentioned, or in other words, to listen to the master of all the albums under the name of achtung baby.