I personally use a brown leather Yoobao portfolio case. It's really an awesome professional looking case. It's made well, has smart cover function, has magnets to keep the cover closed, and has a built in stand. It has cutouts for everything and is really an attractive looking case. And it's cheap for the quality. It comes in black, brown, and red. Just make sure you get the version 3 case. All three sell for less than $26 each at amazon.
Black- http://www.amazon.com/Selling-Yooba...4P2Y/ref=sr_1_1?ie=UTF8&qid=1336424939&sr=8-1
Brown- http://www.amazon.com/Selling-Yoobao-Executive-Genuine-Xengadget/dp/B00588V22Y/ref=pd_bxgy_pc_img_c
Red- http://www.amazon.com/Leather-Case-iPad-Version-Xengadget/dp/B00588VAGW/ref=pd_bxgy_pc_img_c
Black- http://www.amazon.com/Selling-Yooba...4P2Y/ref=sr_1_1?ie=UTF8&qid=1336424939&sr=8-1
Brown- http://www.amazon.com/Selling-Yoobao-Executive-Genuine-Xengadget/dp/B00588V22Y/ref=pd_bxgy_pc_img_c
Red- http://www.amazon.com/Leather-Case-iPad-Version-Xengadget/dp/B00588VAGW/ref=pd_bxgy_pc_img_c
