I'd have to say Enterprise by a nose. The basic idea was good -- take away all the goodies and let space feel like a dangerous place. Unfortunately it wasn't well executed.
Archer seemed like a piece of wood, and it seemed like he had two emotions -- nuetral and angry. You could tell when he was angry because he looked like

. Other than that, nothing. Trip was good, the British guy was good, and they make it a touch more watchable, but it still wasn't *good*.
The stories were pretty predictable. They seemed to be hand me downs from other Treks, nothing really distinguished an Ent story from a Voyager story other than them doing a Search-Replace to change phasers to phase cannons. I think it would have worked perfectly well if they would have tried to think out what it would have been like to be on your own without unlimited power and supplies, and without a clue what was out there.
The final nail though has to be the vulcans. Not that they were radically different. They were a little different, but not enough to be annoying. What *did* bother me was that they'd always know exactly what was going on.
Something like:
Enterprise arrives at Rigel 5.
Archer: I've never seen anything like *that* before!
T'pol: Those are Verdians. They have this lighting organ in their chest so they can shoot lightning at you. I was here on vacation last week, I had a great time.
Archer: OK then.
That's not exploration, that's a field trip.
