First off I should point out that I'm also a fan of the RE franchise and loved the original series ever since I started playing them in 2000. When I stared hearing word about RE being turned into a live action film 10 years back I was looking forward to it at the time.

Originally, according to what I read over the years, George Romero, The famous horror film director that inspired the RE frachise, was actually asked to write a script for the live action version of the game after making a "Japan only" commercial for RE2. Romero was skeptical about it at first, but later changed his mind and wrote a faithful film adaptation of RE1. Surprisingly that got rejected by CAPCOM since they wanted to take a different approach to their story and not reenact the first game.

This is probably why CAPCOM chose Paul W.S. Anderson instead. This may have been a bad move from CAPCOM at the time, but it actually turned out to be profitable having Anderson and Milla Jovovich on board in the end. It's no surprise that the main actress of the films(who plays Alice, an original character) is married to the director.

I might as well nit-Pick each one of the films. If you agree on it or not, that's fine.

Resident Evil
Good:Borrows minor elements from RE1 and RE2(The Licker the Mansion with an underground lab, zombie dogs, Raccoon City, escaping the lab by train, among others).

Bad:Wooden acting, Michelle Rodriguez playing the "Tomboyish army brat" character (and still does to this day...), Very little character development from the supporting cast (because Alice steals the show) .

RE: Apocalypse
Good: Borrows elements from RE: Code Veronica and RE3 (T-virus outbreak, Nemesis, Jill Valentine, Carlos Olivera, Alice emulating Claire's scene from RE:CV) and a funny GTA reference.

Bad: Most of the cast is still bland with a few exceptions here and there.No Leon Kennedy because He was"killed of", according to a newspaper report in the film. Takes place in Raccoon City During a "heat wave", though you can tell that the actors were freezing their asses off while filming the graveyard scene in Ontario.

RE:Extinction
Good: Referencing the Mansion from RE1 and 2 again (Claire Redfield, Wesker,Tyrant and the infected crows make appearances), most of the story somewhat deviates from the previous films and offers a different setting.Seeing More of Alice (Literally, since she was cloned several times by Umbrella

Bad: some of the good supporting characters from Apocalypse were killed off. Same Bland acting. Tyrant was killed off in a very disappointing way(No Rocket Launcher?) and Claire looked looks like a Sarah Connor ripoff.

RE:Afterlife
Good: Referencing RE4 and 5 (mutant dogs, Superhuman Wesker, Chris Redfield, Claire Redfield looks hotter, The Executioner and the Plaga infected civilians appear, the Iluminados Pendant is used )

Bad:Though acting is a little better, it's still obviously bland. 3D Slow motion effects are too gimmicky and tedious. A few plot holes. Jill Valentine appears during the Credits.

So, are they worth watching? Well I don't know about you guys, but I see the franchise as a guilty pleasure. I mean, yeah it may be bad at some parts, but overall I see it as dumb fun if you lower your expectations a bit. I guess that explains why the film franchise is the most successful film adaptation of a Video game series.

To be fair, at least Paul W.S. Anderson is trying his best at it, unlike other directors with their VG and anime adaptations these days. :/