Me too. Measured in lines of code output, my optimal distribution of interaction probably looks like a Laffer curve. Too little and I distract myself often, too much and I spend all my time interacting and not much on code.

Put me on a job where interaction is also beneficial (pair programming, XP, working with a newbie, supporting QA at the next desk over) and I'm fairly sure I'm much more productive overall in a moderate-to-highly collaborative environment. Silent solitude sounds miserable. Completely miserable.

Agreed but I love it however I usually have IRC open on a different workspace in one of the channels I've hung out in for years so if I want to shoot the breeze with someone I can talk to them - I work for a manufacturing firm and I'm the only programmer so I can't really talk about my job in any depth with non-programmers anyway.