Stockholm, Sweden:

Unleaded 95 octane

11,69 SEK / L = 1.50 USD / L
1 US Gallon = 3.79 L

1.50 * 3.79 = $5.70 USD / US gallon

And I feel that's a pretty fair price, albeit still a bit too low (about 70% of it is government imposed tax).
The gas price doesn't seem to change people's minds the least of a bit - the city is still filled with 'em... the usual yada-yada in the mornings with double parking, parking in bike lanes, general swamping, traffic jams... However, bicycling is also obiqitous. Worth mentioning is that the Government is starting up congestion charging in Stockholm, which will hopefully make my through-city commute easier soon