Something not mentioned so far is the line of metal (stainless steel!) cock rings by Gear Essentials (and some others, I guess, but GE makes the best)
I've got personal experience with one of these (it was my first ring
) and also the silicone mega-stretch type rings. So, because they're a fixed size, the GE rings require sizing to make sure you get a good fit... it's pretty simple, as you just take a string or thin strip of paper and wrap it from the top of your shaft, under your balls, and back and divide that length by 3.14 to get the diameter.
On to the difference between these and the silicone ones (when worn the same way) - the silicone one does have the desired effect, making my man-member more "full" and such, but the silicone can sometimes create the same sticky feeling of "balls stuck to thigh" in a different area. As for the metal ring, it's quite comfortable once it's on (I even wear it as a kind of unseen jewelry once I'm out and about) and it's a bit of a turn on, just feeling the weight of it there. As far as in the bed performance, it definitely wins over the stretchy kind, as there's no way it's going anywhere, and, aside from filling up my man-member very much, it also gives me more control over my orgasm and overall feels very nice to wear. GE makes a bunch of different designs of these, and the larger Imperial and Omega are said to be big enough that even *she* can feel their presence. The Titan .2 and .4 are more conservative, and more comfortable to wear around all day. They even come in mirrored, brushed, or charcoal (anodized?) finish... It's quite attractive, too - at least that's what HedwigStrange said when I first revealed to her what I was wearing under my trousers