Technicly I haven't bought a Smash game yet (money problems). But I'll say which characters really really made me want to buy brawl. First I'll say my history with smash first.
Long ago, in the distant past. I went to a friend's house to play some N64 games with him and his brothers. I didn't recognize some of the characters at the time because I only played games on the NES, Sega Genesis, and a few on the PC (Quake2+Mechwarrior 2 and a few RTS games specificly). I only knew about Pikachu+Jigglypuff because of the anime (even though I had a tendency to watch other people play pokemon battles against each other because soo many people had gameboys when I was a kid).
After watching them play a few matches and they let me play. Since Kirby, Mario, and Luigi were the only characters that I've played with in a previous game before, it was a weird experience. Mario has always seemed boring to me. Luigi i only liked more because of him being player 2, so I didn't really choose Luigi because of that. Kirby I liked, but I didn't choose him because of the awesomness that was Fox McCloud. Sometime in between matches I did try Link once though.
Safe to say I lost every match. But that's okay, later that day I won a 3v1 against them in some donkey kong game when they claimed to play that game a lot (and they claim they didn't play smash as much as that game) and it was my first day playing it which made me feel awesome.
Smash 64 just made me want to play games on the N64 in general, and it made me get curious about the roster, I looked into it a little bit. So some friends let me play some games the characters were from. Pokemon, Super metroid, Zelda series, and Donkey Kong.
A few years later, got Gamecube+Pikmin as a present, Not sure when I got SSBM but I got that as a present as well.
At the start I basicly used all the characters to unlock everything and get used to their attacks and such. I used Fox and Link mostly before having everything unlocked because Star Fox was still one of the more awesome video game characters to me at the time. When Marth got unlocked, I had a tendency to use him more than anything even if I didn't know who he was. I liked him for his gameplay because he had decent speed, but his range was awesome, and had a counter, and a good amount of floatiness to him. I am a sucker for Long capes though, and he decent looking sword.
I also tried to use Samus and Mewtwo (who at the time was my favorite pokemon cause of his movie) from time to time but would usually stop playing them quickly because they just control so weird compared to other characters, so I was basicly just playing them because I love the characters (but link+fox I love the characters, and they have the most fun playstyles).
While I have played SSBM with other people, it wasn't very often because people either wanted to play online games on a PC, or have me play some other console at their house. So whenever I did play anyone else, it was a one sided fight everytime. So I did 2vs2 against appropriately leveled CPUs or 1v3 with the other person teamed with level 9 computers.
However, the majority of my time playing SSBM was either playing through Adventure mode, or just having sword battles between Marth+Roy vs Link+Y.Link. Because I'm a sucker for hearing swords clash with each other. Whenever I wasn't doing that, It was all random Free for all with items on high for maximum chaos. Or keeping myself outnumbered with CPUs in hopes of a challenge.
Since then I've done a bunch of research on all the characters in the roster .... Except for Captain Falcon, Ice Climbers, and Game+Watch. I played enough Ice Climbers when I was a kid. It'll be hard to top Captain Falcon's FALCON PUNCH and SHOW ME YOUR MOVES! spam. I looked at Game+Watch but it'll be a game I probably will never play since it looks like games that come with kiddie meals at resturaunts now.
Now as for Brawl.
I've only played it for less than 5 minutes currently as of this post. In those 5 minutes, I played as Meta Knight in a free for all match in a somewhat popular place. Someone playing Sonic walked up to a wall, I just held down the A button and I got that person from 0% to 400% damage with them being unable to escape, which had me laughing pretty hard because I wasn't expecting to see something broken so quickly, and because of the fact I was beating the crud out of sonic (I like the character, but he's boring and can be a jerk sometimes so I also hate him). Around 450% damage on Sonic a Ness player came up to me and just insta-KO'd me with a fully charged smash.
After taking a minute to cool off, I left the room, because I pissed the Sonic player off so much with my laughing, and preventing him from escaping that attack (It's rare for me to laugh, but when I laugh, I laugh loudly). I figured I'd leave so I wouldn't let that player have a bad day just because I'm in the same room.
Extremely hilarious, but very embarassing.
As for the characters themselves:
In general: It's just all the new characters, and changes made to the old ones combined to make me want to get brawl. I'd have to say Charizard, Meta Knight, Pit, Lucario, R.O.B., Sonic, Snake, are the main characters that make me want to buy Brawl.
Pokemon Trainer: I don't care for Ivysaur at all. Squirtle I kind of like, but Charizard is one of my favorite pokemon, Cause dragons (I don't care if it says Fire/Flying, he's a dragon)
Lucario: One of my other favorite Pokemon. He's being all ninja like, and has that aura thing going on which makes him look pretty good.
Wolf: After Player Starfox Assault and seeing small clips of older Star fox games, Fox McCloud seems more boring to me. Wolf is a character that has my interest now so I look forward to playing with/against him in brawl.
R.O.B. - I don't know why, but I always loved the R.O.B. as a kid, even if it was completely useless when I tried to play Gyromite with it. It was better to just press the button myself. Why I still love R.O.B. so much is beyond me. Maybe somewhere in my subconscious he reminds me of Johny 5, which is a movie I loved as a kid. R.O.B. just looks kind of cool in general anyways and I tend to have a soft spot for robots.
Toon Link: Warning! Incoming opinion! Toon Link is like Young Link, but better in everyway. I never liked young link anyways. I used to hate Toon Link, until I got around to replaying zelda games, and Wind Waker is more fun to replay because of it's well controlled, faster paced swordplay than other zelda games. Then it's simple charm sort of grew on me. I would have to say I like T.Link as much as regular Link, and they are too hard to compare.
Pit: No one I knew had Kid Icarus, so I was never able to play or hear about this game. However, Pit in Brawl looks pretty awesome, and his gameplay looks really fun. I like bows, but bows in games are usually done in a boring way. Pit's archery looks really fun, and it turns into daggers. I plan to use this character because of what some people call me in real life as well (I won't say what it is though). I'm only worried about angering players if I decide to spam arrows or the HIYAYAYAYAYAYAYA suddenly for fun (much like how I avoid playing Kirby cause I like to use that annoying taunt too much).
Meta Knight: My favorite character, from my favorite Non-smash nintendo series. I wanted to played him and get Brawl so badly. However, after playing Brawl for those few minutes, and discovering the existence of tiers, I probably won't play him all that much because I don't want people to think I'm just using a character because it's OP.
King Dedede: I never really cared for DDD that much in the kirby series. He looks fun to play as though.
Sonic: I want to play as Sonic, but at the same time I don't. I love fast gameplay, but I know for sure that I'll make people angry by spamming "You're too slow!" all the time. It's the main reason why I don't play Kirby against humans in Melee.
Zero Suit Samus: I prefer samus with her suit on. I haven't seen Zero suit samus much outside of Brawl or Other M, so my mind will associate her with Other M's story. So it'll be hard to look at the zero suit form since in Other M she apparently isn't allowed to be a badass unless someone says so, and Ridley having a habbit of pinning her against the floor/walls.....
Lucas: I like his character and gameplay more than Ness. Note: I've only done minimal research about earthbound, so I could be wrong about liking lucas's character more than Ness.
Wario: He's a weird character. I like him but I hate him. Not a character I'd buy the game for.
Olimar: He looks gimicky. I like Pikmin, but not that much, and Olimar looks boring.
SSB4:
I want to buy it for Megaman mostly at the moment. I'm also curious to see how the characters have been changed, and how the game feels. I'll want to try out WFT, Villager, and anyone else they might add at some point too.
