There are lots of albums out there where I like every song. The things is that with music, it's simply not possible to factually call something better than something else. Even answering questions like 'what is your favourite song/band/album?' is very difficult for me, because it's very dependent on when you're asking, or what I'm feeling like. Calling something your 'favourite' then, in essence, becomes rather meaningless, if you can have a new favourite thing the next day (or hour). When I did the Album top 50 thread(s) on DTF, I named Images & Words as my #1 album and that's probably what I'll still default to, despite not listening to it for more than once every year (if at all) these days. It is an easy answer however, because it's the album that sucked me into music first and foremost. Had that been something else entirely, my tastes might have been different, or might name a different album as my #1, but who cares, really?
This is another interesting issue. I don't think naming a favorite is meaningless, but I think it's context-dependent. Does "favorite" mean the album I most want to listen to today, or the album I want to listen to the most times over the next year? Or does it mean the one I've enjoyed the most across the whole of my life?
I think that last is what most people mean, and I think it's definitely hard to measure because you're ultimately trying to measure your emotional responses to those albums. Those can change day-to-day, so you're really trying to measure the average across time. I know when I've done top 50 songs lists on here, I've made decisions in the particular rankings that I know were too high or too low to capture how I feel about a particular song on average across time, and were based on my feelings during the days or weeks when I made the list.
I think the challenge of doing this is one of the reasons why people like to do the "if you could only take one/five/ten to a desert island" thought experiment. It gets you to think about your preferences from a long-term perspective, because the scenario pressures you to pick not just the album you want to hear today or tomorrow, but the album you can imagine wanting to listen to for the rest of your life.
For me,
Images and Words is an easy #1 for my favorite album of all time. But I literally haven't listened to the whole studio album straight through in over two years. How is it my favorite? It's still the one that means the most to me now and has meant the most to me across time. And when I do the "desert island" thought experiment, it's the first one that comes to mind, always. It's just that I know every note by heart and want to spend the majority of my time exploring other music, with the knowledge that IAW is always waiting if I want to return to it.
I think you can still like or even love albums, even if there are moments on an album that you don't like. In fact, whenever I'm listening to albums, there's never a song I will skip. I just don't do it. It's part of what makes something enjoyable as well; if a song/album/band doesn't have any low points (for you!), then it can't have any highs either and everything would blend together in a one-dimensional sameness. Again, that's my idea of how this stuff works, don't take that as a fact.
I also never skip songs when I'm listening to a full album—to me, doing that is a unified experience that I don't want to break. That's not to say I never listen to songs individually, but they're two different kinds of listening.
I sort of agree with your perspective that there have to be some not-so-high points in order to have high points, but I think there can be such a thing as a really high baseline with really high highs that stick out for being really high highs. To take IAW again, I think the baseline quality of any part of that album is really high, but things like the F#5 and Petrucci's following solo, the opening section of Surrounded, "I was told there would be no one to call on when I feel alone and afraid," and a few others still stand out as even higher highs.
Even answering questions like 'what is your favourite song/band/album?' is very difficult for me, because it's very dependent on when you're asking, or what I'm feeling like. Calling something your 'favourite' then, in essence, becomes rather meaningless, if you can have a new favourite thing the next day (or hour).
I follow what you're saying and agree with most parts, but for sure Dream Theater is my favorite band, they are at the top of the progressive (metal) mountain and not a band even comes close. Pink Floyd would be my follow-up, with Metallica in their shadow. But Dream Theater fills about 95% of the music I listen to. That has been so last couple of years and will be like this in the future, I pressume.
I think there's a challenge for those of us who are more long-time fans to talk about this with newer fans without coming across as dismissive of your preferences or dampening your enthusiasm. But I think a lot of us had a period where it felt like Dream Theater was most of what we'd ever listen to, and then over time that changed. That's certainly what happened for me. Not to say that my love for the band and the music is gone, not to say that I never listen to them anymore, but my listening habits did change and generally widened. Also not to say that will for sure happen for you. But it's a common enough experience that there are plenty of us who remember experiencing that shift in listening preferences and that widening of our musical worlds.