As I'm banging my head on my desk before leaving work this evening, I couldn't agree more with Bulldog's poetic waxing about California.
I did, however, have the opportunity to do dayhikes in the Alps for a month during the summer of 2001. Before having gone over there, I was thinking "Alps, Schmalps! Nothing holds a candle to the Sierra". However, after my month there, I was whistling a different more equitable tune.

The Sierra and Alps are both wonderful, each in their own way -- they are just ... different. So I do think the Alps holds a candle to the Sierra, just in its own special way. In the Alps, there are zero dangerous animals of any kind, and there is also its world-famous hut system. My recollection is that tree line in the Alps is quite a bit lower than in the Sierra -- a pro or con, depending on your personal preference (more scenic vistas sooner on the way up, I suppose; but less shade in the sun). As for the variety of hiking/climbing opportunities, both mountain ranges offer a ton of them.
But since I'm a displaced California boy, the Sierra will always hold a special place in my heart. On the other hand, if the USA ever implodes in a catastrophic way, I'm moving to Switzerland.

CaT