I've posted a couple of times earlier this year. Figured I should copy the last one and put it in 'Road Trips' Forum for easier access, though not much traffic there to say the least.
http://bearinsider.com/forums/showthread.php?p=538225#poststopWould say if people want a hotel within walking distance of campus or downtown that isn't a 1 star, book soon.
Right now, these are best options for mid ranged ($100-125) are the:
1)
Best Western Golden Buff (rooms are a bit dated, but clean and well located)
2)
Best Western Boulder Inn (nicer rooms than 1, but farther away from downtown)
3)
Outlook Hotel (basically next to Boulder Inn. maybe a half step down in quality)
More $$, but not outrageous (~$180):
Millennium (closest to stadium, nice large outdoor patio on the creek, often pregame events)
Downtown, the
Boulderado is a great location, but it appears they've sold all their cheaper rooms and are now left with only $350+/nt rooms.
If you are really set on a nice hotel, the Omni and Reconnaissance in Broomfield have dirt cheap rate son the weekends (~$100-$125). It's not too hard to get to Boulder from there, but anything outside of Boulder (or downtown denver) will be very suburban, so I think that's missing out on the Boulder experience. There is a decent bus system in Boulder, so some of the more corporate hotels in Boulder aren't too bad for getting to the game, but if you want to go out after, parking downtown is tight and taxis get harder to get after midnight.
For anyone younger (or for that matter, anyone really), standing outside on Pearl St Mall at 2am when all the bars let out is something to be seen (I'd suggest outside Old Chicago by the late night Gyro Stand). But tracking down a taxi afterwards is not easy.