I've had quite good experience with the Case-mate barely there cases, they provide the adequate protection with a range of colour choices also.
But at the same time I am deciding between several other cases as well, I definately won't be investing on more than one case though, for I don't see myself keeping the phone too much longer, around 6 months perhaps when the summer holiday comes and we may see a few more surprises.
PDair HTC Incredible S Leather Case
]HTC Hard Shell
They all have their own selling points, I have never really had to complain about both Case-Mate and PDair but they serve different purposes for me in someways, the Case Mate is alot more casual, and the PDair is mainly for work.
The Hard Shell shown by Mobilefun seems a reasonable choice but price is TBC, if it had other colours coming soon it would be great as well.