year since PSU joined the BIG10.
I grew up an OSU fan and I remember PSU joining the conference. They were independent before they joined the BIG10, and Pitt was a team they played yearly, because they're not very far apart geographically (136 miles). Per se, they haven't developed a natural rivalry in the conference more than usually OSU and/or Michigan, who are in their same division (East), and are usually battling for the division championship to make it to the conference championship.
Pitt would be your best bet.