You know I am right
I have the first iPad since day one and has gone through about 10 different kind of cases.
Apple Case
Twelve Twelve book case
Dodocase
Hard plastic case
Silicon case
Sleeve
Leather folio
combination of screen protection + back protection (hard or soft)
Smart cover + sleeve
Dodocase is cool and will get you LOTS of compliment but it is not durable, mine has a developed a crack.
The best one by FAR is the Apple case. I have had the original iPad with a screen protector on it with Dodocase for a while, it was fine but the cover of the dodo case makes contact with the screen and rub the dirt into it. The Apple case with the ridge sides doesn't do that.
The back only case for the original iPad doesn't give you a front protection (now it does with smart cover.)
Sleeve, of any kind, sucks. Why? Because you got to take it out to use it and when you do take it out, you are holding onto a naked iPad and whilst that is fine at home, it is not convenient on the move. i.e. on the train when you are reading it and the conductor as you for a ticket. In a hurry where do you put it? yes, back in the sleeve, but where is it since you are holding on the iPad? oh, yes, in your bag above your head racking. It is a big faff.
Back cover (£5) covers the back.
Smart cover - protects the front AND give you that magnet open feature and the folding stand feature
The ridge of the back cover on the side also create a tiny gap so the cover does not rub dirt into the screen.
In daily use. I just close it and it is covered front and back. I can put it down knowing it is covered, i can throw it into a bag not worrying about it be scratched. I can use it by just opening it. It is thin. It is light.