It seems there is a little bit of a misunderstanding here.
First of all, these "impressive list(s)" are only possible because of the work of all the people who submit new albums early to the VGMdb, fleshing them out with additional information like preliminary artist information, and so on.
What I merely do is to go to the respective calendar page and go through this list, doing a selection of albums that pick my interest in the process.
If it might seem, that I know the games/animes that I list here, then this impression is mostly wrong. In fact I haven't played even one Shin Megami Tensei title as of today. Probably 90% of my soundtrack collection comes from works (game, anime, film) that I don't know. Phrasing it even harsher, I probably won't play/watch most of these works anyway. To give an example, I really like the music from the Ace Combat series, especially The Unsung War, The Belkan War and Fires of Liberation. In my opinion it offers a very good mix of these electronic and (partially synth) orchestral elements. However I will never play any of these games, and the reason is that I'm not particularly fond of aerial warfare. Another example is the Atelier series, which has brought forth some of my most treasured soundtracks. Still, the central aspect of Atelier gameplay is item crafting. And I find this incredibly boring, so now way I'm ever going to play something like this.
For me a game and its soundtrack are decoupled, in the sense that I don't need to know any game details to enjoy a (IMO) good soundtrack. I think I've said this before, but for me a good albums tells a story in itself. Knowledge of the work which it refers to might intensify this, but still, for me to regard something as good, it should "work" on its own.
That's also the main problem I see with some of the people here, which seem to focus too much on the "do I have any connection to the respective work?". Which brings me to the next point, which should discuss how I do these selections.
Yes, of course I also select based on game series. If I've enjoyed the music to a game series so far, I'm more inclined to also give the music to the sequel a listen. This might or might not be rewarded. Here you can again use Atelier as an example, since Gust always has a lot of fluctuation in their composer team. If you follow the series musically, you're bound to discover new artists on the way... artist which you might even like. Like I said, sometimes this doesn't get rewarded, e.g. for me with the Silent Hill and Halo series, which I felt turned into utter crap. But that's not the point. Point is to give even new artists a try and also to have a look left and right.
If you listen out of purely nostalgia, you're going to hit a wall sooner or later. E.g. I'm at a point where I just don't have much time anymore for "serious" gaming. I'm an old-school gamer. If I play a game, then I'm at least playing two hours or more. I detest the type of games (mostly casual ones) where you play for like 5 minutes, then do something else, and come back to it the next day. This isn't gaming for me. I'm also not reading a book if I don't have enough time on my hand. I need time for the immersive effect to take place, so that I can really relax.
So I lack time but still don't want to completly sever this connection, so I keep it via the music. My primary focus is the composer itself, but it doesn't stop there. If you look closely there is most of the time a very complex network of relationships between artists. Take a composer X and go through the albums he's credited for and follow e.g. arranger or performers from there. That's what I really like about VGMdb -- you can discover entirely new and exciting things just by following the linking. All it takes is a bit of adventurous spirit.
I therefore very much disagree with the statement about the decline of interesting soundtracks. The only aspect that has changed over the years is the amount of effort to isolate it from the rest of the "noisy" background.