Like the afore-mentioned REI Power Stretch tights, the Half-Zip top is mandatory winter wear for me. It is one of the few pieces of gear I own where I literally can't think of a single feature I'd change on it.
Improved from the original with a small zippered pocket, complete with "headphone port," or what we here in the less-edumacated boondocks call a "hole," it also now features a full-length zipper flap.
This flat-seamed beauty defines versatile. I use it as expedition weight fleece on big mountains, as a stand-alone top for cross-country skiing, and as lounge wear when kickin' with Hef at the mansion. It insulates well, breathes great and it has a wider range of motion than a pole dancing mongoose. Just buy one.