Favorite audio format other than Dolby/Atmos?

My 5.1.2 system can do Atmos, so when that's available that's what I tend to utilize. When Atmos is not available I tend to just go with "Dolby Surround," because it will also utilize all my speakers and I've been too lazy to dive into other formats mainly because I've already set each channel's default level so that it sounds good for the Dolby formats.

Anyway, just curious: for those who prefer something other than Dolby Surround and Dolby Atmos, what do you prefer and why?