On my Ravelle, I have a wide leathered strap with some recessed silver webbed lightning bolts on it - it's thick to spread the weight of a reasonably heavy guitar and lightning bolts are instantly cool.
8)
On my Strat, I alternate between a genuine Fender Tweed strap (because it looks retro as hell) and my favourite black-and-white checked Levy's one. I think Levy's are pretty much "the standard" in terms of straps, I've had a few Planet Waves but found the leather on each end a lot weaker than Levy's.