I have posted before of my abject failure at fitting a suitable clasp to one of my G Shocks, the last one I bought did not have a wide enough gap between the spring bar, and the clasp to allow for the extra thickness ofthe G Shock resin strap. Now, I know this mod won't be for everyone, but I love it. It makes the watch feel more 'grown up'. No, I don't really know what I mean by that! Here's what it looks like:
The clasp was very inexpensive, and as such, I would judge the quality to be 'ford' standard rather than 'rolls royce', but it is more than adequate for me.
Oh, and here's where I got it...
22mm Stainless Steel Strap Watch Deployment clasp BLACK replacement parts | eBay