Group shots are usually on my 'list' when photographing weddings. Not only do my couples typically request photos of them with their family and closest chums, but quite often parents and grandparents specifically ask for certain group photos.
Group shots can be formal or informal. I discuss specific preferences and group lists in advance of the wedding, which helps me to plan my coverage (but I do love a group shot with laughter!!)
For those of you planning your big day, I have just a few suggestions that may be of some use....!