I had a clone of Sour OG from a buddy a while back. Not positive where he got it. Pretty sure it was Chem '91 x Sour Diesel though. It threw nanners, and wasnt' very pretty herb, but it stunk to high heavens of skunk. Like brand new 6 foot carbon filter still smell it from 2 blocks stunk. It was some of the tastiest bud as well. Might still be around.
However, I think the skunkiest I have smelled was some Bubbleberry back in 1996 or so. That stuff was crazy. You could smell it for days if you left it in your car even briefly. Could be nostalgia though. That particular clone is not around to compare. The guy growing it got busted when his neighbors complained, and his trash was searched. This was out in the country. The neighbors were several miles away. o_O Damn them...