As far as I know, there is not a “group report”, per se. But a number of reports can be filtered by group. If all you want is a list of names in a group, then the easiest one to run is probably the Individual List report with all the options turned off.
The reports I can think of that can be filtered by group are as follows. Obviously, some of them might be useful as a “group report” and some of them might not. For example, the Missing Info report will not list people in the group who don’t have Missing Info so it’s not very good for making a “group report”. I think the best reports for making a “group report” are the Individual List and Custom Reports. The trouble with the Individual Summary for making a “group report” is that it has too much information for just a list and each person is on a separate page.
- Individual List (lots of options, Parents or not, Spouses or not, Children or not, Facts or not - good “group report” with options turned off)
- Individual Summary (each person on a separate page, lots of options)
- Custom Reports (can include spouse and marriage, but as already discussed it can be messed up as a marriage report when there are multiple spouses or multiple marriages for the same spouse)
- Birthday List
- Fact List (if you run it for the Marriage fact, it does not list the spouse)
- Missing Info List
- Multimedia List
- Statistics List
- WebTags List
- Who Was There List