I liked most of the movies individually, but as a group....I have never seen such a disregard for continuity in any franchise. As for The Source...well I really didn’t like their interpretation of the "One". Basically it didn’t matter if there was one Immortal or one thousand left alive. One special one had to beat the guardian. I liked it much better when it was one Immortal left standing.
As for the series...I loved it, but at the end it wasn’t fun, exciting and cool to be an immortal any more. It became a burden. Look at the last episode when Duncan sulks off to no one knows where, leaving everyone on the barge shaking their heads. It could have ended better.
Even worse is that, instead of the PTB for the franchise standing up and saying 'You don't like it, too bad. This is what we put together, this is how it stands.' They caved to the fans and made HL:III which was a bad bad bad rehashing of the first movie.
They could have done great things with The Raven, but it seems that they stopped carring. Which makes me wonder why they bothered in the first place.
It doesn't help either that their star was wacked mentaly durring the whole thing. This is not a personal assessment of her, this is from the interviews with the director, cast and crew on the DVD set.
The problem with "The Raven" is that rather than doing it right and introducing a whole new female immortal character or using a well-liked immortal character (like Methos), they dredged up a character that no one really liked and who had been developed as much as she could've been already and tried to make her the lead on a show. Sorry, Amanda was not strong enough to lead a show.
And if you love bad movies, grab HL's 4 and 5 and you'll be all set! =)