I know there is no such thing as best, it will always depend on the situation. But anyway, in my opinion a basic community has content management, forum and picture gallery. I have created sites using Mambo CMS and integrating it with Vbulletin forum. Works great. I also wanted to have a picture gallery. But it is always difficult to find a CMS solution that ha sa good integration with a forum and a picture gallery. It seems that the new Gallery (by menalto) will integrate well with Mambo. But then, I still need to integrate with a forum.
Any suggestions on complete solutions or easy to integrate?
You could look into using "bridge" to allow you to chare a member database between your cms and another application such as a forum. There are a vew available that have been designed with certain apps in mind. There may be such a script available for Mambo.