Best time to visit Brazil?

My wife and I are considering a trip to Brazil. When is the best time to visit with regard to things like weather, prices, avoiding mobs of tourists, etc?

We stayed there in July-August 2002. It was winter there, so low season.
Climate also was good, enough to go to beach, about 30 C during the day, and 15-20 C during night, in places like Rio.

Winter (June to August) would be the low season, but if you`re looking forward to going to beaches south of Rio you could be disappointed as it can get pretty damp and cold. The north/northeastern section remains pleasantly warm during winter.
High season is December through the end of February. Christmas/New Years & Carnival are the two main festive seasons and virtually everyone will be on holidays so prices do tend to soar. The whole coast gets very crowded during this season. Weatherwise it`ll be very hot (around 40 degrees) and sunny with the odd late afternoon thunderstorm.
If you can, your best bet would be to visit Brazil in the shoulder seasons where the weather is often great and there`ll be no crowds.