Blade is interesting, because the longer it went on, the worse it got. Not just in the movies themselves, but even in the first movie.
Blade started out amazing, but I honestly thought it got weaker as the film went on. The first half of the movie is perfect, but then it kind of starts going downhill.
Blade 2 had some neat ideas (the design of the Reapers was phenomenal), but the CGI fight scenes were just atrocious.
And Blade 3 was just...ugh. Dracula was terrible (it looked like they went to some random nightclub in Europe and just grabbed some dude and told him he was going to be Dracula), Jessica Biel was awful (yes, she puts in headphones when she walks around killing Vampires and uses a laser bow, makes total sense). At least Ryan Reynolds was funny.