Everyone knows them, but I always have to suggest the Red Hot Chili Peppers if people haven't delved deeper into their albums. If you're looking for slower/relaxing music I'd suggest: Barefoot Truth, Band of Horses, Chris Thile, Death Cab For Cutie. Jay Brannan, KINA GRANNIS IS THE BEST EVER, Lindsey Stirling, The Lumineers, Margot & the Nuclear So and So's, Minus the Bear, Mumford and Sons, My Morning Jacket, Regina Spektor, Ron Pope, Scale the Summit, Young the Giant. If you're looking for rock/metal/reggae/funk I would suggest The Black Keys, CAKE, Dead Sara, Fair To Midland, Flobots, Incubus, Marcus Miller, Metric, Muse, Passafire, Placebo, Protest The Hero, Royal Blood, Scars On Broadway, Sick Puppies, Sixx:A.M., Volbeat. If you're looking for rap/EDM I'd suggest Bad Meets Evil, Bassnectar, Caravan Palace, Childish Gambino, Danny Brown, Excision, Infected Mushroom, Karmin, Kendrick Lamar, Pegboard Nerds, Seven Lions. Tech N9ne, Watsky, Yelawolf.
Anyway, hope you find something in there that interests you! If you'd like more suggestions, just ask I have plenty more lol