Note: I recommend trying to torrent all of these before actually paying money for them. a) It's cheaper, knowledge shouldn't cost money, and b) try before you buy, in case you aren't satisfied. Check library.nu first too, they have a crap ton of hard-to-find books.
Ok, so I didn't reply to this for a while because I didn't have the perfect answer, and I was hoping to find the perfect answer over the weekend, but then that never happened. Anyways...
- QFT: Can't offer any help on that, I only have one book on it (QFT in a Nutshell) and I'm not sure how happy I am with it. That being said, if you can download a free copy then the introduction and such will give an overview of the theory and everything, I just wouldn't expect to be able to follow the technical details of the subject that well (although you may do better at it than I have). I don't even feel comfortable giving a description of it, you'd probably do better with wikipedia. It's pretty high level stuff though, actual material for post-doctoral research and stuff, so from one point of view you might as well just skip classical physics, SR, QM and all that (barring needing to know that to understand this) and go right to that, if you're interested in trying to develop actual new theories. One of my physics professors in college even said that the average researcher wouldn't be able to solve the basic problems from our classes, they mainly just knew how to work with this kind of stuff.
- SR/GR I can actually make some recommendations on. I'll just list them along with explanations:
Relativity: The Special and General Theories by Albert Einstein - This is about as easy as it gets, although I didn't really like it that much because it doesn't go into that much detail, and I felt some of the explanations weren't really as clear (they're explained, but it's easy to get confused and it doesn't necessarily address the common points of confusion, like that relativity of simultaneity isn't just due to the delay in the time it takes light to travel, it's that if two observers in different frames calculate what time the light left the source they will get different times). It's too dry to be entertaining to a complete lay-person, and not technical or comprehensive enough to really be worthwhile to someone like you or me (I think, this statement may be presumptuous of me).
Any of the undergrad level Modern Physics textbooks, like the ones by
Tipler or
Harris - I have both of those, they're actual college course books, homework problems and everything. Special relativity gets covered, not totally comprehensively, but in way more detail than you'd get out of the above book. There's also a focus on calculations and problem solving and stuff, example problems, etc. Plus they'll contain stuff on other aspects of physics, e.g. quantum mechanics, particle physics, nuclear reactions, statistical mechanics, etc. They're basically intended as intro. level material to all those subjects for physics majors at sophomore or junior level.
There are
a bunch of other books that focus on special relativity, but I honestly haven't read any of them. I mainly just mention this because with the above two they'll still be leaving out some material, like the stuff about Minkowski space and non-Euclidean geometries, how the magnetism arises as a result of applying special relativity to charges in different reference frames, etc. I'm not sure which books might cover all that as well though.
If you're feeling ambitious you might just jump straight into general relativity:
A First Course in General Relativity by Schutz is good, and the first 10-20 pages have a
very good review of special relativity that made me understand it better than any of the above books every did. It's worth checking out just for that alone (and another reason you might just skip the above and start here).
You'll also want to brush up on tensor analysis for that, for which there's a good online book here:
http://arxiv.org/abs/math.HO/0403252 - Not incredibly comprehensive, but makes a nice introduction. Reading it before or along with the above or the next few would probably make the math somewhat less daunting.
General Relativity by Wald is one of the things I'm reading now (and probably will be for a while). It's a full, comprehensive, no-punches-pulled book on GR. One reason I bought it is that it's recent and takes a modern approach the subject. It's very much a math book as much as a physics book - expect lots of proofs and math theory before you even get anywhere near the real physics. I'm rather happy with it though.
Gravitation by Misner, Thorne and Wheeler is often referred to as 'the Bible' of the subject. I have a downloaded copy that I haven't read, and reviews are generally mixed. It obviously wouldn't be as famous as it is if it wasn't good, but it's also almost 40 years old and 1200 pages. At this point I'd probably recommend the above one over it.
Other random physics books I might recommend:
-
Principles of Quantum Mechanics by Shankar
-
Introduction to Modern Astrophysics by Carroll and Ostlie
-
Introduction to Electrodynamics by Griffiths (he also has ones on QM and Elementary Particles, but I haven't checked them out)
- Any of the
Problem and Solutions on <subject> series (a collection of questions from PhD qualifying exams)
I own all of these, except for Gravitation which I only have in PDF format.
