Is the future groom a lover of a famous reality show? Ask the bride-to-be for a list of favourite foods, objects, or smells that are related to their relationship (e.g. chocolate, strawberry bubble gum, game of Scrabble. Please try to keep this somewhat sanitary and safe!)
Blindfold the participating groom-to-be and have him feel or taste the appropriate items. Keep in mind any allergic reactions the groom or guests may have. Depending on how you want to play this game, the bestman and groomsmen can also participate and support their guy! So… how about a chocolate-dipped Scrabble relay?