On anything over 50 miles I wear spandex.
On anything in warm weather where I don't have to look nice, I wear rapha fixed knickers (rapha quality control is so bad I would never recommend these, but I bought them a while ago). I hear the swobo knickers are similar but better made.
On cold weather rides I tend to wear jeans. Commuting I wear whatever I'm wearing at work unless it is hot enough I will sweat a lot.