Early Decapitated is my absolutely favorite (tech)death ever. I can easily find more technically impressive music, but it feels like good songwriting with is not very common in that genre.
The Polish school of death metal (with those early Decapitated albums) really brought a new wind to the scene. Other bands around that time worth listening to: Yattering, early Vader, Devilyn, Dies Irae, all from Poland if i remember correctly.
Necrophagist to be mentioned just because still relevant 20 years after. First fragment, Gorod, Inferi, Somnium, Stortregn, Solipsismo, Spawn of Possession just to name a few...
Was technodeath a typo? Because mixing Death metal with some kind of techo / electronic genres is available within the death metal scene. But i guess we are all referring to tech(nical) death metal here.
Additions of some bands that i really like: Wormed, Septycal Gorge, Putridity, Defeated Sanity, Archspire.
Origin, Soreption, Archspire for some groovy brutal-tech. Gorguts and Ulcerate for some disso/avant-tech and maybe mix it up with a little tech-grind with Discordance Axis and Gridlink.