My "best" helmet is a Specialized S-Works - I use this on long rides on the road bike. It's light, really well vented and fits my head much better than my previous one, a Giro Pneumo. Fit is always going to depend on how your head shape interfaces with the manufacturer's expected head shape though...
I've also got another helmet (for night rides and round town rides when I decide to wear one or where Ms S instructs me to wear one) which is a Met (possibly a Crossover). It's got a light in the tightening mechanism dial, which is a nice feature. Fit's not as good as the Spesh, and it has quite a short chin strap on it for some reason. Does its job though.
The Giro Pneumo got binned on account of damage. It had some cracks in the glaze from having been crushed while air-transported in a bike bag, but I figured they wouldn't impact it structurally. However, the rear right dents and cracking in the polystyrene occasioned by my pothole-induced sideways dismount at 20mph were certainly structural, so it got slung...