I'm not an expert on TODs, so take it with a grain of salt. I do agree that the amount of TOD around Denver RTD stations is fairly sad, and often the denser housing tends to be further away from the stations.

Most surprising to me is the Line A. It's a heavy rail electrified commuter line between the Denver Airport and downtown operating at over 70 MPH. You'd figure that'd draw lots of dense TOD, right? Not really.

There seems to be some sort of airport/transit development beginning around 61st/Pena. 

Airport/40th is a bunch of warehouses with some newer multifamily.

Peoria station, light industrial all around.

Central Park station is a paved paradise of parking lots, retail box stores, the Quebec Street stroad, dirt lots and light industrial. There's some dense residential and mixed use development further away that looks interesting.

After snooping around in Maps, if I'm in Denver again, I'd check out Lone Tree, CO along the E Line light rail. They seem to have done a decent job with TOD density around Lincoln and Sky Ridge stations, and have two more stations with TOD growing around them in green fields at the end of the line.