How many gears a car should have?

Btw i am talking about everyday driving enjoyment. I drive a 2006 5M Saab 9-3 but i drove most kind of cars: from vw beetle 4A, to nissan 350z 6M, to merc Cl 550 7A. With the lexus IS F and its 8A where do we wanna reach? 10- 12 gears? Is it gonna take us 1/2 hr to reach a gear in order to overtake a car on the freeway? In despite of the recent trend I really like the 5M