My first HM game was Tree of Tranquility; I was hooked after playing it. I love the farming, dating, animals, and festivals in the HM games. It's also fun to complete the main storyline as well. Harvest Moon is probably my favorite game series. They're so much fun.
My first ever game of Harvest Moon was FoMT. Wow, that game is amazing. It's one of my favourites. I remember fondly those memories of when I had no idea of what I should do and got stuck, not even knowing how to go to bed lol. Good times :´)