I myself just recently bought a '07 Civic Hybrid UK spec model after much debate and searching. I also checked out and drove a lot of Prii (plural for Prius I think, lol), none handled nor drove the way I wanted them to be like. After 3 months of searching, debating, more searching and more debating, I got the Civic hybrid. The car is awesome, it has great acceleration (pick), gives great fuel average. I get 16 KPL with it using full time AC and sometimes I do get 14 KPL with 4 people on board. Yesterday, I went to ShahDara with 4 people on board with full time AC in and out of traffic jams, the car gave me 18 KPL keeping in mind that I could only cruise at 70 KPH for a few seconds or so. It even gave me 22 KPL while I was on way to Lahore, when I switched off the AC, the gauge read 25 KPL and I was like
People here don't actually know the true practical aspects of a car, they just say what they think is right; not what facts say.
If you get a "full option" Civic hybrid with the full leather interior, leather door cards, 6 CD changer, multi-function steering wheel, cruise control, heated seats, VSA, adjustable headlights, trunk spoiler and all those other goodies, you'll never think of buying a Prius.
IMHO, a Prius is way, way ugly than any Civic. That hatchback shape reminds me of a Mehran, if one buys a car only for the sake for fuel economy then one has WASTED his money.
Listen to your heart, drive both the cars. The decision is up to you not us. Its your money, spend it the way you honestly want to.