I was wondering what the highest atmospheric entry velocity of any lander was at Mars, for direct-entry landers (as opposed to those released from an orbiter), the atmospheric entry velocity tends to range from 5.6 km/s to 5.8 km/s, this is the case for landers such as Mars 3, Spirit, Opportunity and Curiosity and this is the relative velocity to be expected for a Hohmann transfer from Earth to Mars.
On the other hand, for Pathfinder I've found reference to the atmospheric entry velocity being 7.5 km/s or even as high as 7.65 km/s, this is partly explained by pathfinder entering retrograde so the rotation of Mars is adding to the relative velocity instead of subtracting from it for a prograde entry, but this should only account for a difference of around 0.4 km/s, meaning that Pathfinder was still going more than 1 km/s faster relative to Mars than any other lander.
Initially I thought that the numbers for Pathfinder I had found might be wrong, but there are numerous references to a high atmospheric entry velocity, the most authoritative value I could find is 7.479 km/s from a paper by NASA/JPL based on an after the fact analysis of the mission:
Some other references to similarly high velocities: 7.5 km/s, 7.6 km/s, 7.65 km/s
Based on my rudimentary understanding of interplanetary transfers, I would assume the high entry velocity is due to a slightly "off window" launch resulting in a sub-optimal encounter with Mars compared to a Hohmann transfer, however I could find little information about the launch or what might have made it unusual.