Buff, possibly with a second under the helmet if you don't have a cap. But the Buff on the face is year-round for me, whether to keep out bugs, rain or cold draughts, or to soak in cold water before riding in significant heat.
I bought a breathable balaclava from Aldi in the summer, they were on offer at £2.50. When i got home i realised that it was a motorbike one. I was going to take it back but i thought for the price why bother. I tried it the other day and it certainly keeps me warm, and it is breathable!
I'm clean shaven but i suppose a beard would keep your face warm.
Chilly weather = buff. the free ones from the mags are all I ever have or use
Proper cold (well into sub zero) = A Gore windstopper balaclava. £3 from a cycle jumble and the best money I've ever spent on cycling gear.
I'm growing a beard at the mo to see how that shapes up as an alternative to either of the above as my glasses get steamed up when I'm properly covered up.