Classics to me are things which never go out of style and have lasted for atleast five or ten years. I adore classics, and I try to build my wardrobe on them, I don't think I almost need anything else than classics.
Some classics:
-a trenchcoat
-a leather bomber jacket
-a peacoat
-a classic scarf such as Hermès
-a white shirt
-pearls
-a little black dress
-black pumps
-loafers
-black boots (high heeled or flat)
-a striped "marine" style shirt
-black trousers
-a leather handbag (in black or brown)
-black sunglasses
-a cableknit sweater
-a black pencil skirt
Those are some items which come to my mind.