The Colorado Center is a nice, shiny new-ish theater. The place is huge, like something out of Gotham City. To me, the multi-story, enormously wide staircase that greets visitors seems flashy and intimidating. The theaters have comfortable seats with pretty good leg room. The "stadium" aspect to the seating is less pronounced than in, say, the AMC 24-plex, but there are no problems seeing over the rows in front. All in all, it's a good place to see movies, with big screens and new sound.
In addition, The Colorado Center has the first (and still only) commercial IMAX screen in Denver. It's also the only IMAX in Denver with a silver screen, i.e., the only one capable of showing 3-D IMAX movies. You can see movies like Michael Jordan to the Max and Fantasia 2000 here.
As of March 2004, ticket prices were about $1 higher for shows in their IMAX theater and their giant-screen theater, so call to verify the price before you go.
Caveat: the intersection of I-25 and Colorado is pretty scary, especially if you're not familiar with it. Coming from I-25 north, you have to cross 3 or 4 lanes of traffic in the space of about half a block. Then, you have to turn left at a less-than obvious intersection. Unless you know the area, give yourself a few extra minutes.
Here are a few facts about the theater, mailed to me from "Basp":
The UA Colorado Center opened in May 1998. It has nine screens, the largest being an IMAX screen; all stadium seating; free parking in either an open lot or a covered parking garage; weekends there is also valet parking for $3. Located next to Dave & Buster's at I-25 and Colorado Blvd. in Denver.