To me 90s PC gaming was dominated mostly by Origin and LucasArts.
It was Star Wars games, adventure games and almost everything Origin put out (Ultima, Ultima Underworld, Shadowcaster, Strike Commander, Wing Commander, Crusader, System Shock, etc etc) Origin might just be my favourite developer, even rivaling Nintendo.
Apart from that there some classics like Battle Isle 2, some more obscure games like Deadly Tide which could only exist in the 90s and of course LAN party games. Duke3D, C&C, Age of Empires, Unreal, Doom 2 and later StarCraft and Counter Strike. Those last two then dominated everything and were the bridge into the 2000s and the first steps into the internet for me.
Also remember when it was normal that you had a joystick but not a gamepad? I bought a gravis gamepad that was a SNES knockoff and played through FF7 and platformers but Joysticks were way more en vogue. All 4 X-Wing titles, Comanche, Strike Commander, Mechwarrior 2 and MW2:Mercs, ... Sims were huge.