Here in Chicago, it's usually cold from mid-September to at least mid-April, so I tend to lean towards warmer clothing for the majority of the year.
For the past few months, I've been wearing a pretty thick coat from North Face. I usually wear some black gloves with that and a hat. But when the weather is more in the 50s-60s, I wear a more sweater like jacket.
As far as shirts goes, I prefer polos. They feel comfortable and look nice.
Pants, it depends. I find myself wearing sweatpants more often than not when it's cold outside, and I gravitate towards jeans when it's a little warmer. During the summer, I tend to wear shorts.
I'm probably one of the few guys who wears briefs, boxers, and boxer briefs on rotation. My usual underwear choice is boxer briefs, but I like briefs for very cold days and boxers for very hot days.
As far as socks go, I tend to wear the longer kind. I could never get used to ankle socks. They feel really uncomfortable.
When I'm in the house on lazy days, I tend to wear my pajamas until at least 2 PM. I'm too lazy to change out of them. For my pajamas, I wear some old shirt that I no longer wear in public and pajama pants.