I think that the series compliments the movie in a lot of ways, it's basically following a similar plot to the movie in the first season, and so you should still enjoy the series if you liked the movie. Richie's character is still pretty unbalanced in the first season of the tv series, but they tone down certain aspects like his rape of the bank teller, the tv series does a different version of that scene which doesn't involve rape. One big improvement for me with the tv series was that the vampires still keep their original personalities, so that opened up Seth and Richie's relationship to be explored more in the second half of season 1 when Seth has to adjust to his turning. Also Santanico's character gets a lot more depth in the tv series

I guess that the fault probably lies with me as I always liked the first half of the movie too a lot more when it was a road movie and focused on Seth and Richie! I am a fan of the vampire genre obv, but I guess that whole campy b-movie tone just isn't really my thing?