I personally have always liked flat leather collars. No particular reason, I just prefer them over rolled, and I don't like braided leather. I ordered one for Kodee from Leerburg:
They are maybe a little pricey, but unless Kodee has a tremendous growth spurt, the one I ordered for him a few mos ago (I bought it fairly big, and it fits great now, with 2 or 3 notches left for growing) will be the only collar he ever has. I also have the 18" traffic leash, a 4 ft. leather leash, and 6 ft leather leash, all to match (all from Leerburg). The leather is very thick, but really soft, and these are stitched AND riveted - most places only do one or the other. They are also handmade by the Amish. I use leather cleaner and then leather conditioning balm on them about once a month, which keeps them looking and feeling new.