Brood War IS the absolute apex. This is the game that started e-sports. It is what defined the modern RTS games. It is also the most difficult game. Flash, the best Brood War player, is arguably the best e-sports player of all time.

I loved the campaigns so much that I spent many dollars to play with the campaign editor in a net bar back then. I never figured out how to recreate the Corsair scene at the beginning of Protoss level 2. It was only after many years that I found out that it requires a script not in the official editor — some modders created a new editor that includes all those “unofficial” scripts.

And it's still popular and actually playable today. Warcraft 2 is not really fun to play. Very clunky control, very outdated graphics, bad story telling. With Starcraft, my only real complain is terrible cinematics which just doesn't cut it today. Otherwise this game is as fun to play today, as it was 15 years ago.

Personally I think Dawn of War is the apex. That game really fired on all cylinders. And then for whatever reason Relic completely abandoned the formula and made the next game something different entirely. Dawn of War 2 remains one of my greatest gaming disappointments to this day because of poorly it stood up to its predecessor.