262 Cedar Ln SE
While it's not a Broncos bar exactly, this place is usually not too crowded and has several rooms with multiple TVs. I've watched several games here, often with an entire room to myself. Alot of Browns fans gather here, but I always thought it would make a nice Broncos bar too.
There are probably better sites to watch Broncos games, but this is where I'll be Sunday at 4pm.