Fujitsu ScanSnap fi-5110EOX2 Pass-Through Scanner

I have been using this about 1.5 years, and scanned more than 3000 papers. it works great without any glitch. It can scan color or B/W very fast. Basically, it works like a FAX machine. Put documents (~20-30 pages), press the button, all the information is stored as pdf file in the computer. It can scan both side of paper simultaneously. It comes with Adobe Acrobat (Not Free Adobe Acrobat reader), so you can delete, edit, extract each page later. It's somewhat expensive, but it's worth it.

Only problem is that glossy papers cause jam. Also, you often see some thin line on scanned image when you use color mode.