I would suggest a long weekend (3-4 days) to take in the whole area, as well as a day trip up to the mountains. I have never lived in Denver, but I hope that changes within the next six months or so. I almost moved there a while back, but we had a death in the family basically right when it was decision time. I was bummed and thought we would be in Houston for at least 2-3 more years, but my wife has recently said it is cool if we move soon.
I visited 3 times in the past year, and I've enjoyed it more every time. I have done a lot of research and talked to over a hundred people from Denver (including many helpful, cool Aggies). Here are some things that I've observed, been told, or read about:
-Places to live: ColoAg95 listed good places, and I am sure he knows a lot more than me. I really liked Cherry Creek: 3 miles from downtown, great shopping, nice scenery. If you PM me, I can give you the name of a guy that helped me out and drove me around the areas I was interested in. He hangs with lots of Aggies. If you want to live in the suburbs, I love Highlands Ranch.
-Jobs: It sounds like you have one lined up, which is great. It sounds like a lot of people go to Denver with out a job & just line one up when they get there. Lots of people want to move there, so many employers seem hesitant to talk to you if you don't have a Denver area address.
-People: Probably not as upfront and warm as Texans (which could be a good thing for some), but they are generally very nice. They tend to be laid back, love the outdoors, less materialistic than Texans, and not as much importance is placed on what you do and how much you make.
Things to do: There is a ton to do, as the mountains are very close and provide many activities depending on the season. I am looking forward to skiing my tail off for 4-5 months out of the year, and playing golf/hiking/rafting/biking/exploring the mountains the rest of the time. I think downtown Denver is great, with a lot of good bars, restaurants, and brew pubs. 16th Street Mall is nice, and there are free buses running up and down the street. All the pro sports' facilities are in, or close to, downtown. I second Boulder being a cool place with some very "interesting" people.
-The quality of life is great. There is a ton do, the weather is very nice, you get all four seasons, it is an outdoor paradise, and so on. It costs a little more than Texas, but it is still affordable.
Things that Texans miss: Whataburger, Mexican food, Blue Bell, friends and family.
[This message has been edited by proudaggie02 (edited 8/18/2008 2:05p).]