I went through so many cases in the first 6 months I owned an iPhone...I wasn't happy each time; there was always something: scratching, the inside lining would stain my phone etc. But, I'm pretty happy with the one I use now.
Pipetto. It's a fairly small company (and I'm all for helping locally-run businesses). I like it cuz it's professional-looking, stylish, and also highly protective of my phone.
http://pipetto.bigcartel.com/product/gold-python-print-iphone-3g-pull-up-case
I have the Black Python leather. It has miro-suede lining that actually polishes my screen each time I pull it out. The Italian leather and stitching is also really resilient (I tend to toss my iPhone into my handbag a lot). My favourite thing about it though, is that it's a pull-up case. It's a very clever design, usable, pragmatic and slick at the same time.
Pipetto.co.uk, is the company website.