Lately... I've been into guitar based bands with female vocals such as Evanescence (Amy Lee), Pat Benatar, Picture me Broken, The letter Black, Paramore, etc.
But I still enjoy: (alphabetically just a few) Alice in chains, Angel of dawn, Anna, Barcode, Bren R, Deadmau5, Dinka, Dio, Dj Rui Da Silva, Scrillex, FFDP, Flux Pavillion, Ghotti, Iron Maiden, KISS, Long way down, Mary J. Blije, Megadeth, Metallica, Motley Crue, Ozzy, Queensryche, RA, Rage against the machine, Ratt, Rush, Sevendust, Silverchair, Simply Red, Slipknot, The Police, U2, VanHalen.
I tend to be "anti" Itune and one of my favorite places to "discover" new stuff is unsignedbandweb.com. Most all of the music is free to download, with lots of Genre's to choose from. I browse through and download what I like then just transfer it to Mp3 player. That site has somewhat pulled me out of the mainstream music and allowed me to find what "I" like instead of what the music industry feeds everybody. I am in NO WAY affiliated or promoting the site, I just use it for fresh sounds. There truly are some great artists on there just browse around and see for yourself.