Having watched some of 24 season one region2 in addition to the region1 I had, I must say I'm very surprised that the region 2/PAL was superior, as I think it was a us video sourced series??
In the past I tried the region1/NTSC via TheaterTek software DVD and alternatively an X-card/PDI/HOLO3D(Faroudja DCDi) at 60Hz scaled to 1440x960 on a 7ft screen.
The PAL copy showed surprisingly slightly less deinterlacing artefacts. The scene where Jack is given his mission brief had a wicker pattern behind the actors which looked reasonably smooth on region2, whereas I remember it aliasing badly in the region1 release.
Perhaps 24 was filmed on high-def or film stock??
cheers,
Rob.