Best After Market Stereo?

I currently am driving a 2005 TrailBlazer LT and I love the thing. That said, I'd like to get a decent after market stereo for it so I can use my iPhone with aux or USB port. I do have radio controls built into the steering wheel as well if that makes an difference for installation. I'm not picky on brands, but I've been told to go Pioneer a few times. Does anyone have any ideas and/or experience on which would best suit my truck? Thanks, Justice Shields