In 1992, Donna was desperate to keep her daughter Vicky away from Grant. She made several half-hearted attempts to seduce Grant and thereby distract him from Vicky. This plot line was never played out and Donna and Grant never came near a romantic situation. Today, due to Grant and Vicky's bitter divorce and custody battle, Grant and Donna aren't on the best of terms.
Mac Cory (RIP)
In 1983 Donna cast a roving eye Mac's way (mostly in the direction of his bank account).
Perry Hutchins (RIP)
Donna flirted with Perry in 1983 despite the fact that he had been her stepson.
Donna tried to get into Sandy's pants on several occasions, to no avail. Even making him the administrator of her hospital only succeeded in angering Blaine.
They went on some dates, shared a few kisses, and signed a dating contract. The relationship never went very far, especially since Donna honestly didn't care for the arrangement. Donna later refused Roger's invitation to Europe.
In 1993 Donna made nice with Hank, mostly to get Iris jealous.