This show only appeared for three seasons, on UPN nonetheless, but I always thought it was pretty cool.
The idea of going back in time seven days (hence the title) to undo a tragic event is pretty awesome.
Jonathan LaPaglia (as Crononaut Frank B. Parker) was a childish but likable hero. Justina Vail (Russian phycisist Olga Vukavich) created just enough tension between her character and Parker to keep things interesting. The show had a handful of other actors who provided solid, believeble (as believable as it could be given the show's premise) and qualified characters to round out the show.
Granted, some of the story lines were a bit goofy, but most of the episodes were inspired by events that were plausible.
Episode for which to look: Deja Vu All Over Again.
The show airs in repeats at 2 a.m. PDT weekdays on Spike TV.
Topher