Wow, you guys sure have a ton of flash carts!
Around here I have lots... but really, it's just all about what you have a use for. If it plays ROMs well, that's fine by me, I don't need to collect for the sake of collecting (at least not with flash devices, LOL)
So basically, what I have is:
Supercard SD (Purple color, I wanted the blue though), Supercard Mini (old version with Boba Fett that doesn't reset the DS when you stick it in), Supercard Mini (with stupid new logo that does reboot the DS... I'm looking to sell that one off so if you want one let me know!), and Supercard Lite (Black).
Then for slot 1 I have Supercard One (Obsolete, I broke the spring and screw too), AceKard 2i, and finally Supercard DSi-One.
As you can tell, I'm a Supercard fanboy! Mainly because they work, they're cheap, and really except the CycloDS nothing beats it feature-wise.
I also ordered a second Supercard Lite and Supercard DSi-One as my DS Lite was recently stolen (sucks, huh?) so I need to replace them. Too bad I can't get the data back...
As to why I have so many slot 2s, it goes like this.
I first got the Supercard SD and Super Key a couple years ago, before slot 1 cards even existed. I had the original DS (Phat), and since mini SD cards are kinda uncommon I figured I'd just tolerate it sticking out a little. Well about a year later I got tired of it being so huge in my pockets so I bought the Mini version, as well as a 2GB MiniSD card. I then bought a Supercard One, making my DS Phat complete.
Well my DS broke and couldn't be fixed by Nintendo, so they sent me a free DS Lite replacement. Meaning I needed a smaller slot-2 card, of course, so I replaced it with the Supercard Lite.
As to why I have an AceKard 2i, that should be obvious... I bought a DSi and needed something working. At the time the Supercard DSi didn't exist. When it came out I bought that one too.