"Hero" is a testament to the lure of star power in the rental market. Featuring Dustin Hoffman, Geena Davis and Andy Garcia, it has one of the most star-studded casts of any movie in the past year. Though not a huge box-office hit--$18.2-million gross--this kind of cast would still attract renters who, for a relatively small fee, would check it out for its star power alone. Retailers in some markets report that it's doing strong business, accounting for its jump from No. 8 to No. 3. If those two crowd-pleasing action movies--top-ranked "Under Siege" and "Passenger 57" (No. 2)--weren't out, "Hero" is doing well enough in some markets to have reached No. 1 by now. "School Ties," the drama about prep-school anti-Semitism that features Brendan Fraser, opened at No. 16. It's hard to predict how this one will rent in the next few weeks. Teens will be attracted to it because of Fraser, but it's a serious-minded movie that will turn off some youngsters. "Dr. Giggles," a slasher flick that grossed $8.2 million, entered at No. 20 and should be very popular among fans of this genre.