Not like there aren't enough replies here, but...
It was mid-twenties this morning, which Is simpler sometimes as there's no decisions needed, just grab the legit cold stuff. 30-40 is a pita trying to keep from sweating. So here's my jam.
LG fleece tights. Sauna over 30 but great anything below. I've learned to wear baggies over which keeps them from riding down and also gives me bonus pockets.
JimV endorsed Gore Tool. Only negative is, it fits pretty snug so layering under can be challenging.
Until today I was wearing a Gore base layer with the wind stopper front and lighter fabric rear. I just got a mid-weight REI base which worked very well with the Tool today. See how it does colder.
Nashbar skull cap with ear flaps. Think it was five or ten bucks.
Neck gaiter from some cheapo retailer.
Nike acg soft shell running gloves. I've never needed anything very warm. I just got a cold weather set of pearl izumi gloves which are probably going to be too much. I generally bring my summer gloves to switch into once it warms up ( I typically ride early).
Between the headgear and gloves I can really regulate temps without messing around with the bigger stuff. In super cold temps I've worn three layers and a balaclava but that's like windy single digits.
My problem is footwear. I ride flats and use a waterproof pair of hiking boots for winter, adding a set of running gaiters for snow. Problem is after spending the summer on my 5.10's I want the grip of the dedicated flats, it's a huge difference. My 5.10s fit a little snug so my feet get cold after an hour or so.
Oh, Smartwool light cushion socks rock.