I recommend an excellent game collections of grandmasters' games.
1000 The Best of the Best by Chess Informant
What are the annotations like? Suitable for Class D players?
Not really : they use a languageless system of symbols.
And you can enjoy the incredible depth and beauty of the game.
Yes, @ScorpionPackAttack, thanks for sharing your analytical process with us. Nicely done!
As a low-rated player myself, and in response to the original thread title, I think the question is whether or not to study games at all. I think most of us, including much stronger players, would argue that studying games is desirable. If not, then what?
So assuming that game study is good, especially your own games into which you have already put some analytical effort, then the question becomes is it better to study bad games or good games. Most agree that playing (and hence studying) games with lesser ranked opponents is not helpful in raising your own bar. (Yes, you need to know the patzer traps, etc.)
That leaves only games played by competent players. While you (and I) may not completely understand the reasons for all the moves, nevertheless it does built a mental database of attack ideas, defensive formations and other helpful things. If the games are annotated by the players themselves, then the effect is (or should be ) accumulative. As you rise in ratings, you play better competition and you either plateau at your level of capability and understanding, or you continue to refine and improve.
So perhaps the answer is that if you believe you have reached the end of your own capabilities, then you might argue that study of better games is a waste of time. I don't know of many players who resign themselves to that self-imposed level of competence.
Any game can be instructive: even blitz is or a low quality because you can learn to punish superficiality or calculation oversights. High quality games such as GM correspondence (and OTB at standard time controls) also have obvious instructive benefit, and one can note things such as potential tactical threats being prevented before coming to fruition, how the center effects play, color complex weaknesses, overall plans, etc.
Game collections annotated by players themselves such as "Capablanca's Best Games" or whatnot are excellent, though the ideas and plans are spelled out for the reader, which is always useful.
As far as plateaus go the higher one goes the harder it is to rise in rating: If one is around 1000 then arriving at 1400 will be the fastest and easiest 400 points a person will ever gain. Learning basic endgames, influence of the center and the kinds of centers, and of course tactics will bring someone there, and studying games greatly helps with those.
Games collection books that look at the kind of mistakes commonly made by amateur players are also useful, imo. A good example would be Dan Heisman's recently published The World's Most Instructive Amateur Game Book.