Red guard for stamina dps. Imperial is still okay for tanking (though Red Diamond is mostly rubbish now). Khajit can also be considered for a stamblade.
Think its whatever gives you the most fun.
My tiny woodelf stamblade hits ridiculously and is pretty slippy to try and kill. And she can run incredibly fast. She is pure melee (dw/2h). tried and tested in both CP, nonCP and BGs
Joined January 2014
PC EU - PvE & BGs & PvP (Vivec)
Grand Master Crafter
For PVP 12% health and 10% stamina isn't going to hurt on the Imperial for sure. Most PVP builds are going to put something into health anyway unless they are purely gank builds.
Redguard has max stamina and stamina regen. The regen is nice because you are going to need to give up a line on a set bonus, or a jewelry enchant to get it on an Imperial.
Red Diamond isn't a great skill for a Nightblade though, and that is where the Imperial loses ground.
It is up to you. The Imperial is a bit more tanky but the Stamblade isn't normally a class you choose to tank with. Imperial would increase survivability and be plenty viable but I don't think it will contribute to an offensive Stamblade build. Its not like you are choosing between Redguard and Highelf for a Stamblade. Honestly, neither race is wrong.
WOODELF / BOSMER. makes excellent use of abilities in more situations. Jump from keep walls or towers when things go south in PvP, better detection reduction (even better with 2 particular gear sets) for all around sneakiness, great for stealing or pick pocketing in PvE. All around solid stam regen. It may look like the gimpy spare tire, but it gets you where you need to go in all situations, not just focused on being the best in one situation.
Only reason i say Imperial is because i play one. Imperial makes a really good nightblade. The health passive synergies really well with the Shadow health bonus %. This means Imperial can get away with using duel drinks and not have to worry about a small health pool.
If you like having more magicka regen then i'd say Imperial.
Neither. PvE related best sNB is Khajiit. Sustain you get from Redguard is useless if you have half decent group, and damage loss is notable. PvP related, I find that if you are ever going to gank (wow so rare on sNB), Bosmer or Khajiit are way better. If you want to play more non ganking sNB for some reason or even play without slotting cloak, Orsimer is best choice.
If you wanna tank as a NB, maybe Imperial is a bit better than Redguard, but both are not even near the glorious Saxhleel master tanking race.
If you wanna use sNB for RP and DB/TG, Khajiit and Bosmer are best races.