Dave Farley is a good guy and the real deal not just a talking head - I worked with him at LMAX which is where he was working when he was writing the Continuous Delivery book and that place had agility and the highest standards of engineering I've ever seen as first class concerns in the business (I was the agile guy and Dave was Head of Development both reporting into the CTO, Martin Thompson of Disruptor fame).

LeSS from Craig Larman and Bas Vodde is definitely worth a look too.