I'll give a politically incorrect answer.
In terms of scanner hardware, it's hard to beat the Fujitsu ScanSnap line (used to be called S1500, now after adding wireless it's the model ix500). Dozens of pages per minute, double-sided, very reliable document feeder, color (not good enough for semi-pro photography, but good enough for documents). The best part: the hardware is trouble-free, and is willing to eat nearly anything.
The only problem is software support. I've used it on Windows and now on a Mac. The software that comes has a clunky user interface, but once you learn to use it, it's efficient and fast. Built-in OCR and automatic .pdf generation (you put the document in, press the button, enter the desired filename in a popup window, and you have a searchable PDF file). I've tried it with sane exactly once: waste of an afternoon. The sane webpage claims "good" support for it; I've never gotten it to actually work. And all the scanning software that I've tried for *BSD and Linux is just awful. I'm sure with enough effort one could assemble a functional toolchain on a free operating system, but I have lots of documents to scan, and no time to fool around with toolsmithing. I would recommend scanning on a Mac or on Windows, and then transferring the files over.
