I know the prices are obscene but I don't think you can beat the Vaja cases.
The ivolution case is the best "Back cover" style case and they do versions with a snap on front cover for screen protection. The Agenda 2 appears to be the perfect folio style case with a typing position out there (Some prefer the Agenda 1 though).
Both have fantastic quality leather, look great and, crucially, do not cover the front edges of the iPad like many cases do.
I personally have the Special Edition Mamut Suela Ivolution Top style case. I went through 5 cases prior to getting it and I just wish I hadnt wasted my time on cheaper but lesser quality cases. It looks great, feels awesome to hold and after using it for a month shows no signs of wear or tear.
The cheaper cases all have some killer flaw - whether it being dust magnet materials (Like the Apple case, the Chinao interior and the Cyber Acoustics folio), lame typing angles for the folio style cases (Hello Piel Frama), cheap plastic grips to hold in the iPad (Like the Yoobau slim). Some of these may seem relatively minor but the point is that the Vaja's seem to be the only cases that I have seen where I can't see a bad thing about them.
Yes the waiting time for them to be made is an issue however even the Agenda 2's now have certain colours in stock.
I know this sounds like a Vaja love fest but seriously I have tried loads of cases and nothing tops Vaja.
Have you handled a Yoobao slim? They actually use a fairly high quality soft touch plastic for the clips.
I was considering the Agenda 2 but the reports that the front cover was a bit floppy (esp what i saw in Macgirls youtube review) coupled with a lack of a way to secure it just had me look the other way, not to mention the price. I consider that way more of a killer flaw than some exposed plastic. But to each his own.