3. Shogo: Mobile Armour Division. Made by what is possibly the nerdiest, otaku-iest studio in the world, Shogo: Mobile Armour Division follows the story of Sanjuro and his giant robot. The only major problem with Shogo was the fact that mech based combat used the same physics as infantry based combat, which led to some clipping problems, but all in all it was balanced. You could pretty effortlessly kick ass in your super advanced mech, but would get your ass throughly handed to you on the ground....and I do mean thoroughly. The difference between mecha and infantry was huge.
4. Red Baron: A realistic World-War I flight sim, Red Baron was one of the other games that dominated my joystick days. You take too much damage, you're fucked. You get hit by incinerary rounds, you're fucked. You try to attack an aerodrome without carful planning, long range attacks and lots of manuvering? AA will eat you alive.
It was a powerful experience, just playing. That, and the "Baron" gametype was just cool. Red Baron/Blue Baron/Yellow Baron. They're might have been a Pink Baron as well. Kinda like keep away, but instead of just keeping away, you need to either A) Kill a baron or B) Get kills as the Baron.
If I think of anymore of the older franchises, I'll add them. If you can think of one, tell me in the comments!