Boxers... yfronts have their place but are usually too restrictive.
.... what?
Oh. OH!
Jeans, then. The garment for all situations. Though if I could get some that fit right, had decently placed pockets and weren't just overly fiddly, I'd have plenty of chino style cargos. Only got the one set and they generally turn out more annoying than anything.
Getting a bit of a fondness for my bike leathers now as well. Water resistant, warm, tough, but still have a bit of give in them. And shockingly they even fit right, despite being secondhand (and i suspect a wrong-gender cut .. but it sorta works when I have a set of work troos on underneath)