EPSON v350 or HP Scanjet G4050 ?

Go for the Epson v350. I have tried both (bought the HP, then returned and got the V350). The HP G4050 sucks big time! On top, it only works with Windows or Mac. If you ever want to use it with Linux, you are stuck.

Epson provides drivers for all OS, the V350 is half the size compared with the HP, it's 2 or 3 times faster (the HP takes about 10 minutes for every single negative at max resolution), and you get a much better quality scan. The software that comes with HP is terrible, you need to spend another $40 in scanning software (VueScan) if you want to get a quality comparable to the Epson. Seriously, the HP software doesn't even support BW film! and it makes all the wrong decisions without letting you tell it what todo. The result: terrible quality scans.

I'm assuming you scan negatives, after all, if you were looking at scanning documents, there are much cheaper, smaller and faster scanners out there.