Which browser game should you be playing right now?! Why, it's very rude of you to jump me with a question like that, but I do happen to know the answer. It's arcade shooter Luftrauser by Vlambeer, a flawless little bit of work that Vlambeer released "with massive losses... and at a high personal emotional cost", which was nice of them.
Seriously though, play this one. Incredible music, plus it's rare for controls to feel quite this good within seconds of the game starting. Footage after the jump.
My pitiful high score is around the 600 point mark, if you wanted something to shoot for.