Bought this box set a couple of years back, watched them, then my wife suddenly asked about them so we just watched all three films in the space of three days.
The original film is still the best of the three, with Wesley Snipes in mean and moody form, despatching vampires in a blaze of great effects throughout the movie.
The second sees him being recruited by the vampires he is killing to stop a new breed of vampire. Double crosses (and plenty of garlic!) abound as this battle unfolds. As a fan of Buffy The Vampire Slayer I can't help but notice the fact that as Buffy progressed there was a time where she almost fought alongside her enemies against a worse foe.
Trinity is seeming to get the wooden spoon prize as worst of the three and I can understand how that would be it's fate. The plot line of Trinity isn't as solid or as serious as the first two but Wesley Snipes still held it all together and the cast around him were pretty good too.
Of all three movies Kris Kristofferson was a very strong support but, for me, the really strong female lead alongside Wesley came from N'Bushe Wright in the original. Mind you I sure wouldn't want to upset Jessica Biel on the Subway!
If you are after a great night of action packed adrenalin rush then all three movies should be suitable. Personally I found this trilogy far superior to Underworld, which lost a lot when it lost Kate Beckinsale by part three.