Know any bands before they went big?

Flyleaf (I got their debut like right when it came out. :XD)
Foxboro Hot Tubs (day one, baby. I friended their MySpace when they only had 190 views :con:)
The Matches (2005)
I'd heard of Paramore before they hit it big. I didnt like them too much though. :XD
Good Charlotte.
Evanescence
Linkin Park (since 1998, I got their cd before people really started listening to them around where I lived)

there's probably more but I'm lazy. :XD

I'd loved Paramore since 2005 or 2006; I can't remember. But I do remember seeing the music video for 'Emergency' play on Fuse and I just feel in love with them. I have been ever since, even if I'm not too happy with the Twilight stuff...

And I don't know if this really counts, since they're not really huge, but I'd been a fan of The Gaslight Anthem since fall 2008. And then when I saw they had a free single on iTunes, my jaw hit the floor.

Gorillaz since 2001. I watched the premiere of the Clint Eastwood video and fell in love. They were one of the first albums I ever owned and no one where I lived had heard of them, not until Demon Dayz.

MCR since 2004/2005? I watched the premiere of I'm Not Okay on tv and liked them, grabbed their first two albums. I don't like them anymore though.

^ I fell in love when I saw I'm Not Okay. I still love that album.

Bullet For My Valentine
All American Rejects when their self titled came out
Parmore when All We Know Is Falling had just been released
Boys Like Girls
All Time Low
Mayday Parade
Armor For Sleep, although they seem to have dropped back into the shadows again
Automatic Loveletter
Cute Is What We Aim For
Eyes Set To Kill
Friday Night Boys
Hey Monday
Madina Lake
Red Jumpsuit Apparatus, Ronnie is such a sweetheart (:
The Rocket Summer
Secondhand Serenade
The Veronicas

There's a lot more, but those are the ones I remember listening to before they were popular that are on my computer.

Gorillaz.

I've known of Avenged Sevenfold since I was about nine. That's eight years now (they've been together for only ten years). My brother loves local bands, so he was a huge fan of A7X when they just started with Sounding The Seventh Trumpet and Waking The Fallen. He always went to their local shows and has met them so many times. Of course, I was too little to fangirl, but I still liked them because my brother did.

Paramore. I liked them in like seventh grade when All We Know Is Falling just came out. Then I totally forgot about them until I saw Misery Business on Fuse.

My sister and I knew My Chemical Romance in 2003, and we both got waaaay into them. I think it counts because it was the only year after Bullets, and they weren't known here (small Irish town) by anyone.
I listened to Linkin Park when I was 7 or 8, but no one else knew them here until a few years ago.

All Time Low, Cinema Bizarre.

All Time Low.
No joke, I used to chat to them online.
I still have the emails from them.
Ah well.

Cobra Starship.
Hey Monday.

I'm sure theres more. Just can't think at the moment.

Tokio Hotel. Just before their American fame.
Cinema Bizarre
All Time Low. Found out about them in about late 2007. Saw them in 2008 before their fame really exploded. And honestly, I can't stand them anymore.
Cobra Starship.
Automatic Loveletter, back when their first EP came out.
Escape the Fate
Every Avenue, though they are still not that big.
Eyes Set to Kill
etc.

Escape the Fate
Tokio Hotel
Cinema Bizarre
Blessthefall
More but those are the only ones I can think of right now.

Paramore
Flyleaf

Young Guns. Loved them since the first time I saw them.

The Script.
Tokio Hotel. (waaaaaaay before american fame)

Tokio Hotel
Framing Hanley
Semi Avenged Sevenfold, because I started liking them just after they released Bat Country, and very few people in my entire region of the United States listened to them until a year or so after City of Evil came out.

White Tie Affair is the one that comes to mind the most.

Panic at the Disco, I guess early '05. I was in 8th grade.
Tokio Hotel... '05 I think. (though I wasn't fan, just knew/heard them)
Jonas Brothers.. around '04 (I wasn't fan xD)
there might be more, but I can't remember.

Black Tide since Nov 2007.
I saw them open for A7X and they were amazing. Zakk, the bassist actually remembered me after the show and said I was awesome and gave me a hug.
He's one of the nicest people I ever met.