I chose Sisters of battle.
1. I love Gothic architecture.
2. I like how (apart from repentia) they didn't make the line provocative (ironically I am mainly order of the valourus heart, but that is from fluff... over look)
3. I love the fluff (in a nut shell an organisation developed to protect the bee all and end all, defends against everything, finds out they are protecting the true evil and kills them, then devoted to what is just).
4. I am happy the line still holds up (I am probably one of the few
SoB players that doesn't want plastic sisters... cause they would remodel and destroy the awesome line I have...
My second choice would be Deathwatch
1. They defend humanity against the greatest xenos threats. Predominately, paying for their sins (contrived or otherwise) as a marine.
2. As an ex-soldier I see the merit in this (volunteered exile to pay for things you had to do for your country/
40k Imperium. However, still doing all you can for your country/the Imperium).