Epps and Greer.
You've seen Guy Standeven in something because the man was in everything.

Epps.

Quoteing beauamusika:
Epps and Katie were my favorite characters.
I think it is interesting beauamusika you liked the characters of Epps and Katie.
People tend to take it for granted in today's times, but back in 2000-2001 when the film was made, having two female characters as heroines of a thriller story was quite a step ahead.
This is especially true in the horror genre. Historically, female characters were often shallow and feeble-minded and their role in the story was very often limited to just being killed off gratuitously.
Some of the writers (and re-writers) of the film stated Epps was based partially on the character of Ripley from the horror "Alien".
The character of Katie changed significantly over the course of multiple rewrites and is rather unusual and complex even to this day.
Dark Castle's next film, "The Reaping" also has two female characters whose roles in the story closely resemble Epps and Katie's.

Epps and Katie were my favorite characters.

Epps, Katie, Dodge, and Munder

Francesca was my favourite but I liked Epps, Santos and Jack too.