Silky smooth roads, tons of different ridiciulous climbs, miles of flats, throw in some rollers, make a lot of the roads twisty but don't get rid of the straights all together. 60-80* all year round, nice and windy (but not all the time ), rain that doesn't last all day and doesn't happen on consecutive days.

Edit: i'm thinking lots of green. Lush country. waterfalls. The water would be clean and drinkable, and fruit/berries would be plentiful. Also, there would be lots of bikers from all walks of life. And they'd all be friendly. I gotsta have my group rides.

Finally, tons of mountain bike trails too. Singletrack and fire roads