The two S-Line cases I bought off ebay for $1.85 each with free shipping are not horrible. But you get what you pay for...
The translucent blue one fits OK, but the phone's camera, speaker, and flash aren't centered in the case's cutouts. The noise cancellation microphone is a bit off-center as well. The case is a bit more of a neon blue than I was hoping for, and I'm not really digging the splotches under the clear portions of the case. You know, where the case sticks to the phone... I really like the covered buttons, though, which help prevent accidental presses. It also seems like covered buttons would help keep the phone a bit more clean over time, as dust and debris wouldn't accumulate in their crevasses.
The black case fits, but its holes don't match up well enough to the phone to be of much use. It does look better to me, but that's simply because it's not translucent. And both cases are a bit too thick near the microUSB port to easily plug the phone in. Not impossible, just difficult.
The one thing I learned from these two cases is that I like matte TPU. I like the way it feels, it seems to hide fingerprints well, and it seems it would hold up well over time. I feel strongly enough about this I ordered one of those matte blue Ditztronic cases. I'd really like covered buttons, so I'll keep my eyes open for other similar cases with this feature.
As for the hybrid case I got off ebay, the seller refunded my money and is now bugging me to change my rating. Time to be honest: the case doesn't seem to be metal, it's very difficult to get the phone into, the cutouts don't match up well enough with the phone, and the silicone lining is too "grabby." Overall, I doubt I'll ever use this case, so it's a good thing they refunded my money.
In conclusion, it looks like I'm going to end up being a case where. :-D