RachyAs much as I hate to admit that I do this....
Greyhound. It's usually about $15 and I believe it leaves at 2 different times during the day. You can pretty much have as much stuff as you need.
There is a shuttle that runs from the airport to the downtown denver transit hub and I believe that is $9.
I've done this multiple times. The people on the bus scare me a little, but it's sooooo much cheaper and pretty much just as fast.
I've done this before, it does work very well as long as your plane's arrival time matches up well with when the Greyhound Bus leaves. The Greyhound dumps you foo at Frisco Station, and from there you can catch Summit County's free buses to anywhere else you need to go. The Summit Stage is chill about you hauling tons of baggage on the bus too (the Summit Stage is chill about pretty much everything). When I did it we posted up in the back of the bus because then all of your crap will be out of everyone else's way as they get on and off.
Buy your bus tickets early, it's cheaper and I have seen them sell out. Just make sure you look at the Denver city bus timetables and give yourself plenty of time to get to the Greyhound station.
inb4 ns collecively shits their pants then rushes into a back alley to furiously masturbate into a dumpster. -PJS.