Business or Smart Casual Tops For Autumn and Winter?

What are some fashionable and stylish tops I can wear that are considered business or smart casual? I don't care too much about the jacket because staying warm is my first priority. But when I'm in the office, I want to look presentable and not too dressed down. I'm sure these tops are good for dates too. However, I don't like dress shirts because I find them restrictive, especially when I'm on the computer for 8 hours straight. I also find them too formal.

In years past, I've been wearing regular sweaters or long sleeve t-shirts, but since I'm going to Japan, I want to do some shopping and bring a new wardrobe back.