[cokernel]

Having used both noise-canceling and noise-isolating headphones, I'd recommend going for noise-isolating headphones, at least if you expect office chatter to be your major irritant. Most active noise-canceling systems do best with constant sounds and not so well with random bursts of speech.

I use Beyerdynamic Custom One Pro headphones and am pretty happy with them. They don't provide complete isolation, but they do block out a lot of sound, and I don't need to play constant music to make up for bad noise cancellation.

For a cheaper solution, wear earplugs and just put on some crappy headphones for the visual signal.

[bellerocky]

When I worked at a big company with an open office wore ear plugs while also wearing earphones, on really high volume. It was like I had my own office.