Maybe money can’t buy you love, but love can get you a free TAG Heuer watch, Weber grill, or $15,000 engagement ring -- provided you’ve got a discerning eye for that most romantic of bling. Think you’ve got the chops? Read on. Because the best part of the wedding (gifts!) comes after the ceremony, Long’s Jewelers -- who’ve been bringing local lovebirds together since 1878 -- has issued the Boston Diamond Challenge. Walk into any of their five Massachusetts locations, and you’ll be presented with two stones, one of a conventional cut, the other a Lazare cut, which produces a brighter, more radiant rock. Place your vote on which diamond is brighter and you could win one of the excellent prizes below -- or the aforementioned $15,000 dollar diamond ring, which is certain to make its recipient want to do more than just hold your hand.