Hi everyone! This is my first post here... and...
ZOMG HALO.
I think a LOT of people sort of dislike this game out of spite. Any time something gets too popular, some people who aren't active fans of it start hating it out of principle (See: Titanic and Independence Day)
I'm speaking specifically about the first Halo game, not 2 and 3 (though both were really good, in my opinion).
Halo did a lot of things that a lot people don't give it credit for. The story for that game wasn't terribly gripping, but it was a perfect method for moving everything along. The setting was awesome, though. I remember just stopping at a cliff to look at the ring for a while and marveling over how cool it was.

Then all the other things they did right... introducing grenades in the way they did, the 2 weapons only system, integrating vehicle combat and control the way they did and the shield recharging system (allowing you to duck for cover until they recharged, which totally changed the way an FPS was played)... The enemy AI was the best for any FPS ever made at the time too (and it stayed that way for a good, long while too)... every weapon had its own strength and weaknesses.
Maybe I sound like a ranting fanboy right now, but aside from just being a really good game, it changed how First Person Shooters would be designed forever and was the most fun I've ever had with a video game.
However, despite this, I don't think it'll ever take my #1 favorite game's spot..
Secret of Mana
SoM was one of the first games I -really- got into. The graphics were really bright and pretty and the story, though it was tragically distorted because of the lack of variable width font, was awesome if you could get past the dialog.
I don't know that any one part of this game stands out as better than every other game (except for, perhaps, the soundtrack, my favorite of all time... but that's a harder thing to judge than something like graphics or gameplay), but this was the first time I really felt part of a video game. I remember what it felt like to FINALLY get to the Imperial towns for the first time, or what it was like to see the bigger story events unfold near the end of the game.

Ahh, that felt good to finally rant about these games again!