IMHO, QBs who did something that really mattered in PSU history since 1978 or so (in chronological order)
1) Chuck Fusina --> Was instrumental in getting PSU football it's first shot at a national championship, and was really the first to open up a passing game at PSU that I can remember.
2) Todd Blackledge --> Of course, first National Championship, great college QB, got PSU over the top even when that '82 team did not have a dominant defense
3) Kerry Collins --> Teams first Big10 Title and should-have-been-share-of national championship. Turned out to have the longest NFL career of any PSU QB that I can recall.
4) Michael Robinson --> Led Team to Big10 title and with arm, legs and heart. Was especially important because team had been in doldrums in years prior.
5) Daryll Clark --> Also a Big10 Champion, was a great team leader who also had talent. One win, maybe one concussion, away from a national championship chance.
6) Trace McSorely --> Gotta give it to him for getting PSU a Big10 title when the team seamed dead to rights early in the season, and was coming off sanctions too. Despite the talent around him, nooone can say he didn't contribute.
7) Sean Clifford (TBD?) --> Won two major bowls, including this past Rose bowl, with PSU. I think his 'legacy' will depend in part on how the team does going forward, rightly or wrongly. IF PSU wins the Big10 in the next year or 2, allot of us will see Clifford's gutty groundwork as part of that process.
Honorable Mentions
I can't bring myself to include John Shaffer even though he won a National Championship (and almost two) because I think the team could have done it without him. I on the other hand would love to include Zach Mills for a variety of reasons but he just didn't have enough success.