I dunno, I think BSG is pretty highly rated personally. It has won an Emmy, a Hugo, and a Peabody, among other things. Most people I know who have watched any of it really enjoy it.
I think the bigger issue is that a lot of people haven't been exposed to it because it's not on network television. It's not even on one of the good cable networks. Also, it'd be difficult for someone to start watching in the middle of the series.
Incidentally, this is an ongoing BSG thread which is where a lot of discussion has taken place about the episodes as they aired

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http://www.tfproject.org/tfp/showthread.php?t=38546