How many brands have been recommended so far?
#1 Question is: Will you be sedate or active?
I've amassed a collection of maybe 10-12 long-sleeved Base layers. They're all very effective at playing their part in keeping me warm
when I'm sedate/inactive.
But it's once you get moving that separates the "good" from the "bad" with base layers.
My favourite base layer when I'm active is a Columbia Omni-Heat zip-neck long sleeve:
http://www.columbiasportswear.ie/IE...html?dwvar_1638531_variationColor=053#start=1
Not cheap. I got mine in 53 Degrees north for €40 in a sale.
On top of that, I use my Montane Volt Alpiniste fleece, Craghoppers Compresslite jacket (for when it's
cold) and Rab Latok Alpine shell.
But while I'm inactive (as on a bike), any of my cheapies from Tesco, Lidl/Aldi, Mountain Warehouse, etc, all do the job just fine.
EDIT: As a hairy man, I find the super-tight fitted-type base layers irritating. They seem to compress my body hair to my skin and it gets pretty itchy.