Certainly depends on the caliber, and the use.

For my .22s I like a Leupold Vari-X III 1.5-5x20. It's a good quality scope and I use it when I'm plinking or hunting with the rifle.
I like a more powerful scope on my .17HMRs. I have two: A S&B 2.5-10x56 on my Anschutz 1717D, and a Kahles 2.5-10x50 on my SAKO Quad. The Kahles is adjustable for different calibers with a turn of the turret.

On my Volquartsen .17HM2 I use a Leopold 1.5-6x42 LRP scope. Hust right for the range of this unique caliber.