Oh, I love 1080. Never played the Gamecube version but it was beastly on N64. Smash Bros is alright. It's not a favourite but I remember having fun with it at my friends' houses when I was as a kid, plus I know the cartridge costs twice as much on eBay so I made sure to snap it up when I saw it in the shop.
DK64 was £22 or something like that. I was going to buy a loose cartridge and the expansion pack separately but it would have worked out more expensive at the time. That's eBay for you, I guess. Majora's Mask was pretty expensive too but that was one of the games I knew I wanted to have, so I had to get it boxed.

It was the main reason I bought the expansion pack, if not the N64 itself.