There's a couple things that got me to playing Brawl.
I didn't like Melee much at first, honestly. It just seemed so much more complicated and unforgiving compared to the original, and seeing as i didn't have a Gamecube, I had no chance to really learn it. I ended up picking the game up because my friends were into it, really. I just wanted something else to do with them.
I never really liked fighting games either. It became more of an acquired taste for me. I've come to notice that because of how fast fighting games move, and because the actual competition is on such a small scale, they are about the easiest way to make friends in the video game community, not to mention probably the least obnoxious brand of gamers. That, and Guilty Gear really showed me that fighting games can be fast, over-the-top, and stylish, not just calculated strategy on strategy. So I was able to pick up fighting games, despite a crummy past.
Brawl itself really took me and my friends by storm. The nightly updates became a wacky ritual, and I just got really wrapped up in the hype. But the game's just everything I could have hoped for. It's a fun game that you can play pretty much however you want, on a lot of different levels. There's room for creativity in just about every aspect of it, whether it's creating the level, learning your character, changing the items and settings around...And it's got all characters that bring back memories, either personal ones of when I first began playing video games, up till recent times when I've gone back to look at the games I've missed.
Brawl is something completely unique, and whether you consider it the best game ever or just another diversion, you have to admit that very few games reach the same level of versatility, complexity, and replayability.