I'm aware of Sidney Coleman's 1975/76 sequence of 54 lectures on Quantum Field Theory. Are there any other high-quality QFT lecture series available online?
The Perimeter Institute has recorded all the courses of their one-year Master's in Theoretical Physics. The courses are given by professors and lecturers from different universities.
For a full list of the courses they recorded in 2010/w011 go to Pirsa.org, and under "4. Collections" select "Course" and "2010". The courses are labeled by the tag "10/11 PSI". (I couldnt find a decent link which neatly lists all the courses)
You'll find multiple courses on QM, QFT, string theory, Beyond the standard Model, General Relativity, condensed matter physics, Quantum Information and many more. The format is also very neat. The Flash presentation is a recording of the class in low-quality, combined with decent photos of the blackboard.
Here are some direct links:
Also check out the courses given in 09/11 (search for "2009" instead), where the curriculum was a bit different (also different lecturers). You have for instance David Tong from Cambridge who gives an introductary course on QFT.
(part II was also given by F. David)
The site also has a large collection of recorded seminars.
... and from Lenny Susskind too there is
and this new course
Lecturer: Herman Nicolai
Title: Quantum field theory
Abstract: The lectures are intended to provide an introduction to Quantum Field Theory at an elementary level. In particular, the following topics will be treated: 1, Basic principle of QFT; 2, Representation theory of the Poincaré group; 3, The free scalar field; 4, The free Dirac field 5, Interacting field theories; 6, Supersymmetry; 7, S-Matrix. The emphasis will be more on general concepts than on specific applications. Therefore, for most of the lectures, only a knowledge of quantum mechanics and special relativity will be assumed.
Lecturer: Erik Verlinde
Title: Introduction to quantum field theory
Abstract: In these lectures the basic concepts of quantum field theory are introduced. Topics that will be discussed are: the quantization of fields; Scattering amplitudes and cross sections; Feynman diagrams; Lagrangian field theory; Quantum electrodynamics; Gauge invariance and renormalization.
For the beginner, there is a great series of lectures by Anthony Zee, author of Field Theory in a Nutshell, available from ASTI here:http://www.asti.ac.za/lectures.php. Some of the other lectures are quite good as well.
The INDICO servers by CERN have tons of video lectures on many different topics, related to particle physics and cosmology.
Although the recordings of lectures from the Perimeter Institute has been done some years now, the Perimeter Institute launched the PSI Online program in 2018, which as of now contains three full courses (lecture videos + problem sets), two in Quantum Field Theory and one in advanced Condensed Matter physics.
An overview of PSI Online can be found in the following link: https://www.perimeterinstitute.ca/training/psi-masters-program/psi-online
Susskind's The Theoretical Minimum now has introduction to Quantum Field Theory (although the title is "Advanced Quantum Mechanics):