XF Media Gallery (XenForo 1st party add-on) allows user albums (which I'm assuming you are referring to). It has extensive permission sets that allow you to control albums (and grant ability to users to control them in several aspects)
ShowCase is not really a "gallery" per se - think of it as what the name calls it - it allows you to SHOW off items in a format you can configure to allow specific fields for.
The RM is for actual download of files - the extensions are definable by you (but realize some browsers will NOT allow certain extensions to download by default).
@Tracy Perry Thank you for the info, one more thing tho, when setting permission to allow them to add media etc... every user will have their own album which only them can add and remove things, correct? or anybody can just come in and add things to the other's user album.?
Also, If I add some images to my album, can I use these images in threads/posts instead of including an image from URL?