Now what do you mean by best link exchange... Quality links are the ones which you get from good websites related to your niche
I would recommend you 3 way link exchange over reciprocal link exchange. If you're looking for a place to exchange links, have a look here: http://forums.digitalpoint.com/forumdisplay.php?f=53
The best link exchange is where you take your cash, and exchange it for a link. If your link strategy revolves around old fashioned, 1 for 1 link exchanges you might as well forget ranking for anything competitive.
What he means is that which is best among the type of LE: 1 way, reciprocal, 3way, etc. For me, 3 way Link Exchange is the best.
As always said..."Good Things comes with a price". You need to either put loads of whitehat efforts or pay to get quality links.