I remember when multiplayer gaming (3 or more) required a seperate piece of hardware since only two controller ports were the norm those days. I bought my first multitap in 1988 for my Nintendo. As other consoles I bought were released, I got the multitaps for them too. The multitaps, though expensive, made perfect sense... it's good to play together! Me and at least two other addicted gamers could play at the same time. It was bliss. Then consoles (except for the PSOne and PS2 damn you, Sony) started coming with four controller ports. Now multiplayer gaming is even easier to experience!
I'll just mention a few of my multiplayer favorites from back in the day.
NES
World Cup
It's River City Ransom on grass with a soccer ball and a crazy sense of humor. 1-4 players
Genesis
General Chaos
Vent your frustrations! Lodge a rocket into your opponent's chest. Or just mercilessly gun him down in the street. Take your pick. 1-4 players
SNES
Super Bomberman
The joys of explosive ordinance! 1-5 players
So, without including online gameplay, what are your favorite games from retro to present that were syrupy sweet when it came to multiplayer (3+) enjoyment?