I use a Bell Delirium. I had a Bell X-Ray, and I really liked it until my bike fell over onto it (cracked). So I got the Delirium as a replacement. I am a big fan of the "GPS retention system". It makes it easy to adjust the size so if I want to throw on a bandana, or a beanie in the winter I don't have to spend 5 minutes re-adjusting my helmet. Just flip the knob. The price isn't too bad at $45. It has a removeable visor, which I like, and I got the silver one so the color is pretty understated.
What I don't like is that the velcro on one of my gloves caught one of the pads, and ripped the cloth covering off of the foam. My fault I guess.