What if Salah ad-Din Yusuf ibn Ayyub (Saladin) was unable to take back Jerusalem in the Second Crusade, keeping the Kingdom of Jerusalem as an established force in the Middle East under Catholic control?
Barbarossa still lives which will have some interesting effects on the HRE as he doesn't drown in a river
Is Barbarossa even born in TTL?
Other than that, I'd expect Guy of Lusignan to remain King, and he and Sybilla might end up having a surviving child given time. Isabella and the Ibelins would remain out of the Inner Circle.
If, for the sake of convenience, Barbarossa IS born, he might not have the opportunity to put Conradin on the throne in Jerusalem, thus the Hohenstaufens have a sporting chance of keeping Germany anyway.