I'm not sure what sort of Music you are into but If you are into Heavy Metal I would recommend A Day To Remember, if you are going to try them out listen to I'm made out of wax, Larry, what are you made out of? and If it means alot to you, those two should give you a good sample of the different genre's they cover. If you're really into Heavy Metal, just send me a message or something because I know hundreds of Heavy Metal bands.
For Techno/Pop I would recommend Hadouken!, I know that they're not everyone's cup of tea but I still think they are great and if you just want straight techno go for Deadmau5, they offer a couple of more potent techno songs as well as some light trance techno for is you just want to chill out, and for dubstep, I would recommend no one else than Mord Fustang, the song Lick the Rainbow in my opinion is just amazing. Another amazing artist would be Yolando Be Cool, they did "We no speak Americano" And "Le Bump" two great songs in my opinion, very up tune beat, especially the first one that I mentioned.
For country music, if you're into it, I would say Keith Urban would be the best just from my personal knowledge.
For casual Metal I would suggest Dead letter circus, I guess it's also a bit indie since no one really knows of them but my Girlfriend and I love them, if you're thinking of checking them out, try out their song "One step" first, and also in this category I would say Disturbed, though they might go into heavy metal, depending on what you classify as "Heavy Metal", if you're thinking of looking at them, listen to their song "Decadence" first, gives you a good taste of what they have to offer.
For Indie music I'd say, The Wombats, I first discovered them way back when they released "Let's dance to joy division" a really good band depending on your tastes, as always. Art Vs. Science is also a fantastic artist, they made "Magic Fountain" which is a pretty hilarious song and also "Finally see our way".
And for Rap and Hip Hop (My Specialty) Just gonna list a few bands, Bliss N Eso, Hilltop hoods, Drapht, Layla, all Aussie rappers, For Bliss N Eso, listen to Reflections, Coastal Kids and Flying Through the City to get a good taste of their work. For Hilltop Hoods, try Clown Prince, Down the Hard Road, Speaking in tongues and Chase that feeling, they're an amazing band and always a pleasure to listen to. Now Drapht, my favorite artist, for a taste of his work listen to The money, Uncontainable, observe, Jimmy Recard (best song) and sound man, his beats are pretty sick as well as his lyrics. And finally Layla, she did a fair bit of work with Drapht, I would recommend listen to Maverick, pretty sick raps.
This isn't all of the bands I can recommend, just a select few for those genre's, Hope I helped.