Bubble Bobble on the C64 was my favourite version, much better in my mind than the PC version or even the arcade version! I remember all those little rituals you did to try and make things happen, like secret doorways and the like- It was a really fun and magical world, full of surprises and superstitions. Also, 100 levels was just enough to tackle with your friend during an afternoon.. There really hasn't been anything like it since.