To begin with, Wing Commander is my absolute favorite game/series ever, period. I'm so happy to see it there, that I didn't have to put it as Other as I would have.
Secondly, 1990 is my favorite year of games. Aside WC there's Monkey Island (another of my top 5 series ever and the first is my favorite) and DQ4 which I consider the best Nes game ever. And I do think Phantasy Star III is underrated, I like it at least as much as the second.
Other list is missing Loom, a beautiful game, perhaps my second favorite Lucas adventure after MI. Another personal favorite of the year is D&D dragon flight sim DragonStrike, And speaking of flight sims, Red Baron.
Sega had roguelike Dragon Crystal/Fatal Labyrinth that I still play annually on my MS. Another MS favorite of mine is Slap Shot (it may be the game I've had longest aside the build-in).
King's Quest V isn't a personal favorite but worth mentioning.
Star Control is still fun.
And Minesweeper and Solitaire appeared same year, from certain perspective big games.