My understanding for how a tier list like this is supposed to work is (i) that there is a minimal qualitative difference between albums within a given tier, (ii) that there is a substantive qualitative difference between albums across tiers, and (iii) that belonging to a low tier != being a bad album (i.e., the albums are ranked relatively to each other, not relatively to the albums of other artists).
My justification for my tier list:
SFAM are IAW are both magnum opuses of two different sides of DT (the "classic" side and the "epic" side). These albums are untouchable, IMO. Regarding SFAM, sure, you can nitpick that the individual songs like "Through My Words" on SFAM aren't necessarily mindblowing on their own, but this is SFAM we're talking about. It's a concept album that's meant to be listened to as a whole. "Through My Words" understood in context balances the bridge between "Strange Deja Vu and Fatal Tragedy" very well. The whole thing is a ride.
Regarding IAW, this is classic DT with delightful melodies, riffage, funky proggyness, soaring and crisp vocals, great lyrics, balanced songwriting. The only flaw I can think of is the production value (especially the triggered snare), but even this has become endearing over time.
SDOIT is amazing as well but does suffer from a handful of elements that hold it back, particularly a few less-than-stellar songs and questionable songwriting. As a whole it is incredible despite its imperfections. I think the same can be said of Awake, SC, and TA.
TOT and Octavarium are sister albums, I feel, one showcasing DT at their heaviest, the other at their proggiest. But there are some real flaws holding both of these albums back. TOT has these long and frankly kind of stale instrumental sections and Octavarium has a set of really average songs. They are mostly pretty good albums though.
BCASL and FII have songs which are hit-or-miss, which is why I can't rank them among DT's better albums. I don't think any song on BCASL is bad per se, and as a whole I do like the album quite a bit, but the quality between and within its songs is inconsistent. For example, you have AROP, which is really unimpressionable, standing next to ANTR and TCOT. Or you have ANTR with its awful outro verse. FII is more obviously bad in the same respect, though it does have its stellar moments.
D/T, ADTOE, and DT12, the three albums which represent "new DT's" approach to songwriting, are honestly just kind of dull in the songwriting department. There are great moments but I never feel like I want to listen to them out of anything but fan obligation. D/T is fresh and interesting and better than the other two, but I could see it feeling just as stale as them in a few years.
WDADU is honestly their one truly bad album, which can be overlooked, as they were just finding themselves. I can understand why DT fans find the album interesting as a curiosity, but there's no doubt it's a bad album. There are some sweet moments, but on the whole the production quality, Dominici's weak vocals, and hit-or-miss songwriting make me confident it belongs in F tier.