Journeyman is the best show not named Lost or Heroes, and, at this point in time, very likely is the best of the three. Part of that is because there is a ton more potential and the unanswered questions thatv are out there are a little more mentally scaleable. while not predictable.
Think of Journeyman as the real life story that Quantum Leap was originally based on (it's not, but just work with me), until it spun into a strong Sci-Fi story of its own. Sam Beckett of Q.L. went to the past to change things that went wrong. He looked the part of someone in the past and we never saw Sam in his own time. J.M. is Dan Vasser a regular guy - with wife and kids - suddenly transporting in time. There are a lot of twists and turns, but suffice it to say that he has no idea why he's jumping back in time - for only short periods - and then back to the present. Except that he learns that he is supposed to change something back in time for whatever reason.
While incorporating one of the mainstays of Sci-fi, time travel, J.M. is a story that takes place in the past and the present. We see the present day repercussions of adding or subtracting things in the recent history (usually somewhere from the 70's through the early 2000's). The journeyman affects his own present day life -- on occassion there are tangible, and even dangerous consequences.
There are layer after layer of storylines within each story -- the one hour conflict, the overarching why & how, as to his time travel, the frequent references to his father (who abandoned his kids when are journeyman was four), and even a former girlfriend who is also a time traveller and frequently helps him on the missions in the past.
Journeyman doesn't ask for, and doesn't pander to, Sci-Fi/time travel fans. But it remains painstakingly consistent in working within, while trying to stretch, the paradoxes that are incumbent to travelling back in time. Especially the warped sense of travelling back within ones own time and often dealing with issues and conflicts that directly affect the Dan's past and present.
The last episode of the season airs Decmber 19. While it is rumored to be in ratings trouble, this is a show that - with the right promotional schedule and the network-confidence to allow more time for the audience to build and the overarching storylines to develop - would be a series for the books. I guess time will tell...