i have been told from others on here that hunter road out of oakmont/verona is the best descent (and subsequently the best ascent) within a ten mile radius of the city. i've never done it, though.
as far as things i have done, there are plenty of solid climbs all around. i'm not sure exactly what you're looking for, but if you can stand rollers, just take any road out into the north hills, and you should be good. if you want to go up, say, mt. troy, you can start it by going up rialto st. in troy hill (pig hill = 24% = fun!) or logan ave in millvale (maxes out around 24% but it's longer and the steepest part is at the top = fun!), or you can find any other ways getting there.
middle road out of etna is at least a 10 minute climb for me. or you can once again take the fun way, which is a very gradual ascent up saxonburg to berry hill, then up berry hill (probably once again around 25% at its steepest) to middle, for maximum fun.
i haven't been everywhere within an hour of the city, so i certainly can't speak to the best climb. but there are plenty of 10+ minute climbs, even within the city. and i promise the north hills has plenty more. and so many others where you think you can suddenly relax because you're going downhill, only to find you've got to go back up even higher once you get to the bottom. love it!