(More) Friends of Mineral Town: This is a Gameboy Advanced game, so if your DS is one of the versions that doesn't have that compatibility, then ignore this one entirely. In my opinion this is one of the least memorable portable Harvest Moons, but it's still a good game. This isn't necessarily a bad thing, but in my opinion AWL was overall a better experience - however, I seem to be in the minority of people who actually liked AWL, so to each their own.
The town is virtually the same, the characters are virtually the same, etc etc. Harvest Moon DS: This one could be called a re-hash of one of the console games, "Harvest Moon: A Wonderful Life". Even still it's one of my personal favorites just because it's so different in many other ways in fact, I recommend it if you're new to the HM series, because it's easier and you can play for a while to decide whether the basic concept is your thing or not.
Also, there aren't really any gold sinks, so once you upgrade everything you need to, the money starts piling up and the game loses quite a bit of value. Your house is fully equipped right at the beginning of the game, complete with a kitchen, a bath, and a bathroom - whereas in others you have to gather wood and stone and actually pay money to get each upgrade at a time.
Grand Bazaar: The reason many people dislike this one is because it's very, very easy compared to any other HM game. I've only played about halfway through the first DS one so I won't recommend it, but I won't advise you to stay away from it either from what I know, the dungeon-crawling aspects are completely optional anyway. Rune Factories: These are standard harvest moon games with RPG elements meaning there are dungeons, monsters you can fight, etc.