The Scintillan Fusiliers are my single, alltime favourite Astra Militarum Regimentum. But The Death Korps of Krieg and The Armageddon Steel Legion both come at a close second for their gas masks! XD

I was going to say, based on your profile I feel like Scintillan Fusiliers,Ventrillian Nobles, Praetorian Guard or the Mordian Iron Guard would be your types.

This image best illustrates what I think about people who like The Death Korps of Krieg and The Armageddon Steel Legion. I'm also a huge connoisseur of The Scintillan Fusiliers myself! XD
https://www.researchgate.net/publication/343598792/figure/fig2/AS:923535321075713@1597199387637/Ah-I-See-Youre-A-Man-Of-Culture-As-Well-expresses-the-admiration-for-certain.jpg

For the Imperial Guard, I like the Death Korps of Krieg, Steel Legion and Cadians the most. Catachans are fun too, but not a favourite. What about you?

The Black Templars are my favourite chapter outside the 20 First Founding "Legiones Astartes." Although this is coming from an admirer of "Die Deutschherren" or "Die Ordensritter" as the medieval founders, rulers, and standing military of "Preußen" as the "German" culture and state uniquely outside of Das Romanisch Reich! XD Otherwise, what's your favourite Astra Militarum Regimentum? :D

Sigismund is actually OP, No other space marine could match his skill. He is the Giga Marine of Warhammer lol. Also the wolves of Fenris are pretty rad, just wish they would chill with all ''Wolves'' in their 40k version. I think the 30k Wolves are much more cool, and Russ is pretty bad ass.