The first movie was okay because it was. It had the most believable characters. Alice wasn't really likable but at least she was human and not superhuman. The Hive was a cool idea and feels like something Umbrella would do. The way the movie sets itself up was more subtle and ambient compared to the later movies as well. There was some actual attempt at atmosphere. There was also at least some tension to the movie as well (being stuck in an underground lab full of zombies with only hours to escape). Story wise, It could actually even maybe work as a isolated outbreak from the actual games.
So yeah, I think the first was decent. But all others after that were terrible. The second lost me when they made Nicholai a good guy who got killed by a zombie dog.