How early to arrive at Charles de Gaulle?

What terminal are you out of and where are you going?

I fly United Airlines and like to arrive at CDG about 3 hours early. This usually gets me ahead of the massive line-up that happens about 2 hrs before UA flights.

My first trip to Paris (3 years ago), I arrived at CDG 2 hours ahead of my flight. Even with being moved forward in the line once a monitor saw when my flight was, I still just barely made it! So now I arrive 3 hours ahead. If you're lucky you won't need that much time, but it makes for a more relaxed experience.

Well, that depends on where you are going...
International is international even inside Europe, and for those flights the check in closes about a half an hour before the flight leaves. Overseas I would say 3 hours. It's written on your fligt ticket...

I took Delta back to LAX, and 3 hours barely covered me for an 11 am flight. We were in line at 8 am, holding our croissant in 1 hand, ticket in another as we waited for check in and then security.

I definitely would give yourself AT LEAST 3 hours.

I would proceed with caution and allow plenty of time. The first time I traveled out of CDG, it was such a frustrating, chaotic event! On a following trip, I drove to Brugge and Brussels for an open jaw flight just to avoid CDG. Of course, Brugge and Brussels were a lovely end to a trip, plus I had the advantage of flying out of a sane, quiet and pleasant airport.

I go Delta and always arrive at least 3 hours early to give me time to get through security which can be slow or sometimes fast. I can't stand the thought of standing their sweating in fear of missing a flight.