Ow, didn't know that so many games supported it. I guess it's because I played mostly first and second party games on the N64, which mostly doesn't require the Controller Pak.Actually, quite a few do:
http://www.powerupgaming.ca/Which-Nintendo-64-Games-Require-a-Memory-Card_b_6.html#.VZYQ4UZ0f5V
And I just read that models of the memory card actually require batteries, and some have EEPROM. Is this true? If so, anybody know how to tell which cards have batteries? I'd rather avoid them.