Sirloin? Medium rare.
Fillet? Rare/blue.
Any steak with sinew/fat so T-bone, Sirloin, rump, medium rare. There has to be enough heat to relax the fibres.
Fillet is really the only steak that should be served rare, blue, or raw. There is flatiron or flank that are best rare, but they're not really cuts one would find in the UK