madwarper said:
Are we including the Rune Factory series? Because, I'd say RF3. It would have been Frontier, were it not for the damn Runey system.
I AM RIGHT THERE WITH YOU! ;_; That game broke my heart.
Frontier was the perfect harvest moon game. The farming was well implemented and felt tight and responsive. The Hack-n-slash fantasty Combat/dungeons was snappy and responsive and actually felt like an organic part of the game. Cooking and stuff was neat and highly useful for the aforementioned combat (Why buy potions when I can just cook some good food and haul it down there with me? Sure I'm vulnerable as I eat, but I heal so much more, and regain MP to boot!). The villagers were a ton of fun to listen to it was just hands down incredible. That and the mail girl was INSTANTLY likeable and immediate in-game relationship material.
And the fact I had to micromanage the fucking runeys floating overhead, with a horribly implemented vacuum cleaner that only sucks up about 4 at a time, at random freaking RUINED IT. Not to mention that you literally CAN'T ignore the system for too long. If you don't micromanage the runey food chain in each area, then they will starve themselves out and your crops will take longer and longer to grow (to the point where if ALL areas go runey free, you can barely even GROW anything, as many of your crops will literally wither on the vine!). But on the flip side, if you don't want to spend a half-hour of real-life time at a spreadsheet trying to figure out what runeys need to go where to keep things balanced, and you turn all areas "prosperous" by filling them with tons of runeys (this makes the food chain stop, and all you need to do it refill the area with Grass Runeys instead of balancing the food chain), which is a million times more manageable...Suddenly your crops grow WAY too fast and now you're stuck harvesting your ENTIRE farm every single day, because it's all regrowing so fast!
Oh, and throw in the fact that the only way to check the distribution of runeys is to go to the second floor of the observatory building and you've got a mechanic designed to enrage.
Seriously, I enjoy Harvest Moon and it's ilk because I want to farm and enjoy a semi-relaxed virtual life with fun villagers. I don't play it to micromanage a spreadsheet with the game on pause, then run around vacuuming up nature spirits to redistribute half the time!
Why yes, I AM mad bro!
--
AHEM.
*BACK ON TOPIC FOR ME*
As to the original question...That's a tough one.
I mean, I've made clear that if it weren't for one stupid game mechanic, I would crown Rune Factory Frontier as the king of Harvest Moon, even though it's a spinoff series.
But I can't.
So I'm going to say Friends of Mineral Town. Why? Excellent townsfolk, tightly designed farming, the feeling that my actions mattered to them, AND it has Karen. Who absolutely ROCKS. Badass alcoholic girl who is fun to chat with and who is also a sweet partner if you pursue her? Hell yes.
And the original SNES game gets a VERY close second place. Why? Because it's all about "Can you save this farm and make a ton of money in 2.5 years? PROVE IT!". Basically, it takes the opposite approach of the other games, which tend to let you farm at your own pace and enjoy a virtual life. You are on a time limit and you need to get your shit in gear! I liked that. Not to mention you need to be a bit creative to make money during the winter, when you literally can't grow ANYTHING, not even grass/animal feed.

I was literally running a chicken mill after my first very tough winter.
As for the Rune Factory Series...
I actually really like Rune Factory 4 (3DS), even though I've kinda put it on hold for over a year for other games (Like catching up on my Etrian Odyssey). The only problem with RF4 is that the townsfolk don't seem all that interesting. I mean, they're not bad, but most characters (especially the love interests) aren't super interesting (Fussy Elf? Afraid-to-be-feminine-but-is-really-a-super-sweet-girly-girl-Knight? Boring-but-nice butler? Dwarf Rival Guy? Meh.), or they have some critical flaw that I can't stand. Like, I LOVE the super sarcastic tsundere girl, but she comes with this INSANE and irritating ghost thingy that follows her everywhere. If they were a bit more interesting and the combat felt a little more tight and snappy, it might be the best in the series. The dungeons feel serious, the plot is interesting, the farming is excellent, and it's got a freakin' pancake loving dragon ruling the town, for crying out loud! ;_;