I did not see anything similar on the forum and it's a question I ask every now and then.
For me, I still have a working copy of Super Mario Land (got it used), with a GBA to play it on. It blows my mind how I didn't have a problem with the small screen back then but I'm also used to having a lot of screens and text larger size to avoid too much eye strain.
I still have a link cable between GameBoys and the printer. Ah, good times when Costco and Target had different colored GBC's and N64's stacked in that big plastic case.
Unfortunately, the oldest thing I'll still have soon will be a DS since I really had to do some spring cleaning and finally had to get rid of old stuff I don't need anymore.
Super Mario Land, in the beginning you baffled me with how come Mario's fireballs went zigzag (at least I could snipe enemies with it) or why Koopa shells exploded. But now, I finally have to part ways with you.
...
Then again, I wouldn't mind getting a used Dreamcast and play some Shenmue or Power Stone (co-worker of mine bought a boxful of those VMUs for a like $1 each).