Ability to import End Credits
I think one of the sections that need the most contribution, especially in terms of time, is the credits. Having to type each name and title into the given boxes takes quite a lot of time and can be a deterrent.
Since for most games the information is already out there, being able to copy and paste the information into a standard format (maybe word, excel etc.) and then import that into IGDB would really help.
Also, being able to edit them even after the changes have been accepted so people can add different languages/voice actors.
Might also be worth saving credit videos if that is going to continue to be the source, because a lot of the videos used have been deleted from youtube.