I don't have HDTV, but I do have a Denon 3805. I've found that the best listening format for 5.1 varies with the program. For music-only programs (e.g. the Grammies), sometimes there is too much info in the center channel for Dolby Prologic II Cinema; on those programs, switching to the Music person of Dolby Prologic II works better. Conversely, on some other programs that are more dialogue-oriented (for example "24"), the dialogue gets split among the front channels on the Music setting, and it isn't as clear as when I switch to the Dolby Cinema. Occasionally, one of the DTS neo options seems to be the best. So my advice: keep some spare batteries for the power-hungry Denon remote and switch around until you find what works best. I have found that the DSP options (e.g. Mono Movie, Stadium) just muddy things up, so I avoid them almost all the time.