There are so many tools its actually difficult to make a final definition of which one would be the best. My team uses google drive, but dropbox also works.
Here is a short list, you would want to go with the corporate version of each
1. Google Drive
I assume you're looking for a tool that can share what's shown on the presenter's screen with other users in real time. There are a number of good web-based tools for this, like WebEx, GoToMeeting or JoinMe. They have free and "pro" versions, the latter of which are fairly robust (I personally happen to prefer JoinMe).
There are also much more sophisticated, video-conferencing based solutions with all manner of presentation sharing capability. Polycom (the maker of the "star" conference phones) has one of the more sexy solutions, which they purchased from HP a couple of years ago. Hope that helps!
If you are looking for a tool that will allow collaboration, version control, auditing, reservations on your document. You are going to want to look at higher end tools. Because of your size consumer products will not pass your IT departments standards based on security and the ability to protect your data, I would look at Igloo Software, Or a SharePoint. SharePoint will cost you a lot to customize to get to that point though.
With 28 countries as well the Tool need to be hosted in order to access, responsive for those who are off site and have a multilingual option in which I know Igloo can help with.