I've had bad experiences with Icon gear, though it was ages ago, so not sure if they've improved. They went so far down the 'streetz-stuntah-dank-wooolie-bro' stying at the time that I completely wrote them off. Probably says more about me than the brand, to be fair...
For good value (i.e. not junk), I think HJC is pretty high on the list, along with Scorpion, KBC, and LS2. I think of AGV as more premium, but they do have some solid value. My experience with the more budget oriented end of helmets is the lining is usually less plush, so an imperfect fit is a bigger issue, as pressure points are harder to hide. If it's me, I'd want to try one on if possible (and for a good 20 minutes), but that's not as easy as it used to be.
One thing I've noticed about helmet reviews is that noise is very difficult to predict. Everyone sits with their head at a slightly different angle and in a slightly different airflow depending on the bike and windscreen. I've had helmets that were whisper quiet for me that others complained were deafening, and vise versa. Making sure the shield is tight and even seems to be one of the biggest factors...