I flipped through some posts in this thread... When I die, my wife is going to have a field day on eBay with my GameCube stuff. I knew some of my stuff was uncommon, but yeesh.
I have five sets of GCN Component cables.
I own two Hori Digital Controllers - one black, one indigo.
I've got five WaveBirds, one of which hasn't even been opened (got it cheap, but didn't need it).
I own six regular GameCube systems - five of which have Broadband Adapters in them.
I own a Panasonic Q, also with the Broadband Adapter. It's been internally modified for JPN or US titles.
Each of my GameCubes have Game Boy Players, including the Panasonic Q with the special Game Boy Player for it.
ASCII keyboard controller. I love that thing.
2 of the Action Replay discs where you can enter your own codes.
Several of the games thrown around in thread are in my collection. Fire Emblem. Pikmin 2. The Metroid Prime/Wind Waker 2-Pack. Twilight Princess. I do want a copy of Pokemon Box though.
More fun for me - I have four copies of Avalanche 1080, four copies of Kirby: Air Ride, seven copies of Mario Kart: Double Dash (I think 4 of them are the copies with the bonus disc...)
I'm not trying to sound like I'm bragging - just was surprised to see all the demand for this stuff. So much of it I picked up super-cheap. Four of my component cables were bought at GameStop for under $5/pair. I knew they were hard to get at the time, but with what they're going for now... geesh.