Best Sci-Fi Space Battles?

ardor asks: "Recently, while watching Babylon5, I wondered about the space dogfights in popular sci-fi outings. I find the space battle in Star Wars VI to be still one of the best in existence, and some battles from B5 are amazing too. But where are more good space fights? I've found them to be surprisingly rare. Most are very short, or not very big (less than 5 ships). I know, large & complex scenes are very expensive, nevertheless I mean some with tons of small interceptor & bomber ships, large/huge cruisers, stations, and so forth. Have you watched a really awesome space battles, and if so, what show/movie was it?"