Themed Albums

I have been thinking a lot about themes in music and lyrics and how they affect songwriting. Songwriting for me has gone through many changes. There were those days when I would write lyrics that were superficial, but necessary to finish a song. I don't regret that at all. I had to learn how to write a song, and I wasn't prepared to access that level of intimacy in myself that will generally give a song an emotional core. I am attracted to that emotional core in other's songwriting, so it seems others would be attracted to that in my own songwriting. Just as an aside--I'm not speaking of the manufactured or over-the-top feelings that often get exploited in music (see "Emo"). I'm speaking of real lyrics. Lyrics that come from inside me and are what I really feel or think (whether presented in a straight-forward way or as sarcasm).
It didn't take long before I began to experiment with my emotions and beliefs while writing songs. Writing songs became much more fulfilling at that point. Musically, it brought me the chance to channel my joy, frustration, or sadness into rhythms and melodies that felt appropriate to what I was feeling. Lyrically, they also gave me a vent that I could turn on to let these things out.
I got to a point in my songwriting, though, where I wanted a greater challenge: I wanted my songs to mean something. I wanted them to be more than just my emotional outlet. The best literature always comes with layers of meaning, and that is exactly what I wanted for my songs: layers of meaning.
I also wanted to craft themes into my songs. This, for me, was something that I had to be careful about; shoving my thoughts or themes down peoples' throats wasn't the idea. This was supposed to be an access to introspection and self-discovery; I wanted to learn just as much as everyone else. That meant that these themes would need to evolve naturally in the songs. Through either telling a story or looking to physical representations of intangible ideas for inspiration and as a way for those themes to tell themselves.
All of this is coming as set up for a project that I am currently taking on. I am analyzing some of the albums that I am most in love with, in search of themes. I don't think this will be possible to do unless I divide it into groups. Otherwise, it will just be too large of a project. I will be looking at outside information in this project (such as interviews given by the artists), but not until after I have spent some time with just myself and the album. I will be looking at it musically and lyrically to see how these two aspects of the song work alone and in conjunction with/against each other. I will be looking at individual songs and at the album as a whole.
At first, I'm going to be limiting myself to concept albums (as I interpret what makes a concept album). I am aware of many concept albums, but I am sure that there are many more out there I've never heard of, so if you know of any worth checking out, let me know.