I watch Enterprise, heck I just love Star Trek, but in my opinion its the worst of the lot. All the other Trek series are brilliant, and then there is Enterprise.
The opening theme music from the very first episode thats what got me. I was just sitting there, after waiting so long for the next Trek series and hearing that song, I knew something was out of whack. And sure enough it was.
The whole series kept the same vibe with me. Things were just out of place. From casting to storylines it was off. I believe this put off trek fans as well as any newcomers.
If your looking for great sci fi may I point you to Star Trek Deep Space Nine.
Season 3 did pick up the pace and I enjoyed 4 equally as well, if not more. Seasons 1 and 2 were tough to get through with Dr. Phlox being the only character that was worth anything.
Its watchable and I watch the show but a different cast, better storylines, and cutting out that song would have put this series up to par.