Here's the grades I use for rating albums. There's some more valuable information about my grading style on How to Use This Blog, which I recommend you also check out if you haven't yet. This system is inspired by Robert Christgau's Consumer Guide Grades but the grades themselves don't always line up. One example is that a B+ by me is an album which I will definitely return to but I know that Christgau doesn't revisit many of his A-'s.
A+: A masterpiece of the utmost degree. What more is to be said?
A: A magnificent album of thoughtful construction, incredible execution, and outstanding listenability.
A-: Likely anyone but definitely a listener who enjoys the artist or genre will love it.
B+: A strong album which a listener who generally enjoys the artist or genre will find quite gratifying and worthwhile.
B: A good but unexceptional album that either is fairly enjoyable all the way through or has such strong highlights that the weak tracks will be mostly tolerated.
B-: An album, although exhibiting a few glaring issues, that is slightly enjoyable overall. It should only be explored in full by listeners who already treasure the artist who created it.C+: Ranging from mostly unmemorable to slightly bad, this is a competently executed album that need not be explored. At best, it warrants a single listen from curious and dedicated fans of the artist.
C: An album which has disgraceful execution that ruins a decent premise or a disgraceful premise that ruins decent execution.
C-: An album which has some, barely discernible artistic integrity.
D+: It would be misleading to classify this album as music.
*: Placed after one of the letter grades above, an asterisk denotes an album that I listened to before I created the grading system. Therefore, the score will not be as legitimate since I retroactively gave the album a grade without a re-listen. In essence, the grade has a larger margin of error.