I have no problem doing a top 10 list for 1990. I just about went broke buying cassettes that year. Although it started off slow, the last half of the year was just an absolute beast in terms of LOTS of great releases. Here are the ones I rated, in order:
1. Queensryche - Empire: One of the greatest albums of all time.
2. Y&T - Ten: I was pleasantly surprised that they could put out something so good so late in their career. After leaning a bit too hard into attempts to draw commercial success on their last two albums, this was a really nice blend of their hard rock roots with the slick studio production and commercialization of the latter half of the '80s that worked really well.
3. Megadeth - Rust in Peace: A true classic in every sense, although I didn't appreciate it until several years later.
4. Suicidal Tendencies - Lights...Camera...Revolution!: I would have missed the brilliance of this album if they hadn't opened for Queensryche.
5. Mother Love Bone - Apple: This and Empire got endless spins from me during my time in Desert Storm. There was such a uniqueness and a melancholy to their music that was perfect for that time.
6. Warrant - Cherry Pie: The vapid '80s lyrics and image, coupled with some of their singles, really distracted from some really solid songwriting on this album.
7. Lynch Mob - Wicked Sensation: This album, coupled with Don Dokken's solo album, really showcased who brought what to Dokken during their '80s run. Lynch really was a fantastic riff and solo composer.
8. House of Lords - Sahara: This one flew under the radar, but had some really solid songwriting and playing.
9. Steve Vai - Passion and Warfare: One of the very few instrumental albums I truly enjoy from start to finish.
10. King's X - Faith, Hope, Love: Discovered this one a few decades after the fact. Really solid album.
11. Depeche Mode - Violator: Probably the last "great" album from them. Really good driving music.
12. Tesla - Five Man Accoustical Jam: To me, all other "unplugged" performances are rated against this one.
13. Cinderalla - Heartbreak Station: Not my favorite from them, but has some good songs. And I appreciate that this was really the album they (or at least Tom) wanted to make.
14. Scorpions - Crazy World: Fairly weak by their standards, but has a few decent songs.
15. Extreme - Pornograffiti: This album is such a mixed bag for me. I don't revisit it often. But there is some solid material on there that warrants a decent ranking.
16. Testament - Souls of Black: Metal classic.
17. Poison - Flesh and Blood: I found this to be kind of forgettable after a few months. But I give them credit for the fact that riffs and parts of songs still just jump into my head to this day.
18. Jon Bon Jovi - Blaze of Glory: Not as good as the full band efforts to date, but was a fun experiment.
19. Public Enemy - Fear of a Black Planet: They were still angry AND wrote some really accessible tunes.
20. Firehouse - Firehouse: Pure fluff, but in a good way.
21. Stryper - Against the Law: An experiment that ultimately probably would be classified as "NOT a success," but still produced some good music.
22. Don Dokken - Up from the Ashes: Not bad.
23. Ratt - Detonator: Can't tell you a single song off of this anymore, but I got some enjoyment from it back in the day.
24. Prince - Graffitti Bridge: This was Prince "toned down," and that worked to an extent in producing some fun songs.
25. Garth Brooks - No Fences: If country was my thing, this would rank a lot higher, as it has some really solid songs.
26. Madonna - The Immaculate Collection: Not a fan, but she wrote some landmark songs, and this collection had a ton of them, so I feel like I have to give some credit. This and the Dick Tracy soundtrack are the only albums of hers that I actually bought.
27. Jane's Addiction - Ritual de lo Habitual: For that time in my life, this was a fun album.
Wow, that was a lot. Again, it was a good year in music as far as I was concerned. Things were beginning to change in the industry. The hard rock albums that are lower on my ranking (and some other bands, like Maiden) show that, and show that some bands and a large segment of hard rock in general, were starting to stagnate. But there was also a LOT of really enjoyable music as well. And I'm probably forgetting about an album or two that were obscure enough to not make wikipedia's lists (although I got a couple from memory).