I've got the forementioned super brilliance bulbs in my car atm, and they are pretty impressive. They're a lot whiter than standard bulbs as well, so they look a bit better.
Incidentially, they're also on buy one get one free at Halfords now which makes them only slightly more than standard bulbs to upgrade. I know we're expensive for bulbs, but for what they are (and bogof) they're pretty good.
I use 100/80w H4's in the mk2 and they're good as well, but not e-marked and therefore not legal. Still no probs though, and noone's flashed me for having bright lights yet
