The Onkyo doesn't belong with the other 2. The 603 might be a slightly newer model than the 3805 or 2500 but it doesn't have the power or the features. If those are your choices I'd do a demo between the Yamaha and Denon, see if there's one you like better for any reason. If you like them both the same go on price alone. Make sure the remote with the Denon is the upgraded model as they have changed remotes for that unit.
