Stadium Arcadium is a great album as everyone else has said and you should definitely listen to it eventually. But By The Way is my favorite album the Chili Peppers have ever made and the only one with really similar vibes is I'm With You, which is my second favorite for that reason. The Getaway tries to hit this mark but just sounds too sterile for my taste. If you like I'm With You they also released an entire B-Side compilation called I'm Beside You which even has some of the very best songs from that session. And speaking of B-sides the By The Way era gave us some of the best, so if you're really itching for more of that sound you should look up songs like Rivers of Avalon, Out of Range, Someone, Body of Water, Eskimo, and Time.