Harvest Moon 64 is one of the most addicting titles I have ever played for the Nintendo 64. Featuring a good balance of farming and character relationship system, its a game any owner of a N64 should get.
While the graphics don't look that great in general, the aestetic style fir the mood of the game perfectly.
The Gameplay is very addicting. You can raise a farm anyway you see fit, buy extension for your house, raise livestock, grow crops, make a field of grass, the list goes on. Also has a deep character relationship system and the ability to marry one of five girls from the town. The game also features local events.