As MI noted, you would not be able to distribute any of the official games and I am sure that the developers of the fan made games would not appreciate someone else distributing their games. AGDI's games already come with an installer and now so does IA's.
The best that you can do is what I am doing, by creating installers that others can use with their own original media. I have
new installers for all of the AGI, nearly all of the SCI and many of the other Sierra Family games. The idea is to make it as easy and convenient for both the less experienced user and the advanced user. Advanced users appreciate them for the convenience, including developers of a certain favorite emulator.
There are installers for DOS, Windows and a few ScummVM games. For the DOS games, my installers will allow the user to specify a specific DOSBox installation or check for the presence of DOSBox in a default location, verify that it is the latest version and download and install DOSBox if it is missing (same with ScummVM for the games that use it), install the game, apply all relevant patches, and optimally configure both the game and DOSBox. They include extras, like high res icons for Vista/Win7 users, a DOSBox configuration tool to allow the user to easily change a few DOSBox settings without having to understand how to edit the dosbox.conf file. Sometimes I have to RE the original installer to find all that is required to install a game. Floppy games may have its resources split and compressed to span it over multiple disks. These games need to have the resources concatenated and or expanded. Some games are are very easy and straight forward to do, like the AGI games. Windows games may need registry entries, ini file entries, system files added and or compatibility fixes applied. I try to be as light on the system and registry as possible, often not adding everything that the original installer did, if not required for the game. Some of these are for games that run on modern Windows, but the installers fail, such as most of the 16-bit installers on x64.
If you want to try this yourself, the two most obvious choices for tools is
NSIS or
Inno Setup. Inno Setup is probably a little easier to learn than NSIS. Its scripting is INI based, but is much more limited. various plugins are available for it to extend its abilities. NSIS is much more flexible and powerful. Its scripting language is described as a cross between assembly and PHP. Though the learning curve is higher, some IDEs that you can get for NSIS include wizards to easily guide you through creating basic scripts in a matter of minutes. I have also used it to create a few basic tools to help me in automating a lot of the work of creating my installers. In fact, the DOSBox configuration tool that I include with the installers for DOS games is also made with NSIS. I used to think I was rather unique in using NSIS this way, but I found out that a lot of people that use NSIS regularly do, too. If you want to do more than a couple of installers, I would highly recommend taking the extra time to learn NSIS.