Mine is a boxer I bought when I was 14 years old (ten years ago) that is worn so much into tatters that it more resembles a knot of string, and the best part is the colour; orange and pink with green stripes.

Oh, and, its become entirely seethrough over the years...

I also own one with Jaws on the front, but that's just classy in my opinion. 

why do you still have that?

OT: I have official "monty pythons spamalot" underwear

I used to have a lot of dull (simple black or grey) underwear and socks... but I have cleared most out and bought some nice new stuff in nice colours (it is quite difficult to find mens underwear in anything other than black/grey/white or dark blue)

I have done the same with socks except with more and brighter colours... I think I may be developing an "interesting sock fetish".

I have a pair of stripy multicoloured socks that go above my knees, and they were only £2.

 Because I love it... The most worn garments are the dearest sometimes...

My Count Chocula boxer shorts.

Actually. I don't own count Chocula boxer shorts. Though now I wish I did.

Or Boo Berry.

Oh well, guess i'll just have to be happy with my Fruit Brute bobblehead.