almost no user will install some custom 3d plugin. browser plugins are huge security risks. so you can't really create a better solution yourself but must use what is already there.



i think webgl would be the best way to do it and it will only get better.

on modern browsers it will work without any plugin, and on ie it will work with a plugin:

http://www.irrlicht3d.org/pivot/entry.php?id=1211
(it is free now also for commercial use.)

i am not sure about the support of webgl on mobile devices but sooner or later they will support webgl too.

and solutions like coppercube can export the same project to flash and webgl. so you could also use flash on ie instead of the IEWebGL plugin.