You should match the key that the rest of your song is written in. However, If you’re starting the track with an 808 pattern you will usually find the keys E, F, and G to have the most power. Keys like C and D are usually a bit low and the sub starts losing power.
All of this is completely experimental though, the best thing is to write out a pattern that you like and then when it’s done, transpose it up and down until it sounds nice and solid.