Between Gatsby and Daisy, love is presented as a romantic and incredibly powerful force in Gatsby's case and a much more pragmatic and malleable thing in Daisy's. Gatsby has lived the past decade by remembering the feelings he had for Daisy prior to the war when she was an impossible dream, out of his reach because he lacked the money and the prestige to give her the life she wanted. This dream has driven him to make huge piles of money, create a new identity and seek her out to win her back.
For Daisy, she isn't quite as sure about what love is as she accepted Tom as a suitable husband, had a child with him, and puts up with his dalliances as a matter of course. For her love is perhaps a thing she can use to get the life of comfort and ease and luxury she is used to.
In the case of Jordan and Nick, it is perhaps slightly less dramatic as neither one of them seems to be greatly affected by their feelings for each other if in fact love is one of them. When their relationship ends, they both walk away with some pleasant memories and some hazy misunderstandings about what it was all about.