I'm still only really discovering all the different aspects of death metal, but I am quite fond of symphonic DM I must say. Makes a nice change from the barrage of symphonic black metal groups. There are still very few groups I've found that play in this style though, just really Septicflesh, Hollenthon, Mayan (which isn't that symphonic despite its branding). Psypheria that I posted above is kinda symphonic, but that's more accurate as something like "progressive symphonic gothic death metal" ;)
And of course Fleshgod Apocalypse, though I gather from what I've read this symphonic death style is new for them.