Tasty sweet treats and food, some nice clothes, great video games, a watch, some shopping vouchers. The list could go on, but it's best to choose a gift that the groom will like! Try asking the groom's family and friends what they think he would like, or choose one based on what you have heard the groom said about something that he wanted.
I believe this practice of giving gifts to grooms is more prevalent in non-Western culture. In this case, I think there are some set gifts that each party has to give depending on the rules of their culture. However on a less traditional note, there are many alternatives that a bride can gift her groom. My suggestion is to get him something that he can use for the wedding day, like a pair of good cufflinks, pocket squares or leather shoes. It will make the lead up to the wedding more exciting!
Engagement gifts run the gambit. Suitable and appropriate options include: Stationary, spirts, entertainment tickets, wine glasses, movies passes, and the like. Do not wait if you choose to purchase an engagement gift for a couple. Typically, gifts that are purchased more than two months after the announcement of a marriage are considered taboo.