That's the only way to go IMO. All my lights have cords but some are green and some are orange, depends if i get the cord at Lowe's (green) or Benny's (orange).
I used to buy the shorter orange extension cords at ACE Hardware, I think they were like 15 feet. Now I only buy 25 foot orange extension cords at Wal-Mart. Except sometimes when I don't have that much money for a orange extension cord, then I just buy one of those brown or white lamp repair cords.
I use 15ft cords with the exception of my OV-25's cord which is 20 or 25ft. I'm not sure why i bought the longer cord. I thought a remembered 15ft being on the box. Maybe it was on sale or something so i bought it...
None of my lights have cords attached to them anymore. I took all the cords off to make it easier to move them around. Although now every time I want to fire any of them up, I have to wire them first, which isn't hard to do obviously but just takes more time than just pulling it out of the closet and plugging it in. And of course, my collection has grown a bit since I took this picture.
Did you keep all the cords? All my street lights in the house have cords but not the ones in the shed. Most of my fluorescents have short 18AWG cords on them (computer cords usually) but not all of them have plugs, some just have wires on the end since I need to buy some male plugs that wire-on.