YOu missed probably the best one.. Sanitred... it stays elastic and it eliminates the need for silicon because they have a primer that will make it permanently bond to acrylic or glass. Its also as easy to use as just painting it on.
I think it's a pretty strong claim to say that any method is the "best one". Do you have some more info to back this up? I have not personally had good experiences with Sanitred. I got a small sample and didn't find that it adhered particularly well to glass even with the primer. I've heard other experienced members (VLDesign and nolapete I think) report similarly unimpressive results.
When I started this thread I wanted to stick to tried and true methods that have been used successfully. If you have links to successful long-term builds using Sanitred please post them.