What are your favourite online games? (across any platforms and PC)  

What are your favourite games that you've ever played online? They can be on any console or on your PC.

For myself, the game I think I had the most fun in ever was Star Wars Battlefront over X-Box LIVE. I used to play it every single night for hours, and made so many friends through the game.
I never got bored or frustrated with it. I learnt every map inside out, and mastered every character class.
Oh how I miss the days of Battlefront *sighs*.
Star Wars Battlefront II misses out, because I never managed to find games which were lag free. I guess it just wasn't popular enough in Australia.

The next game in line is probably Gears of War on the 360. This game is just sheer brilliance, and it's one of the few games where I constantly played with friends night after night after night.

Next up is Halo 2 - A game which ate up at least a year of my life. Halo 3 doesn't topple it yet, because I don't find Halo 3's multiplayer to be anywhere near as strong or as fun at this point.

And thus ends the list of my top three.

Star Wars Battlefront - Xbox
Gears of War - Xbox 360
Halo 2 - Xbox