[hbbio]

The list of old Apple devices that still work well is impressive: I still have one original iPad, an iPhone 3GS, several iPhone 4. Same goes for the more recent ones, with the exception of the few devices that I dropped on hard floors over the last 10 years...

[mattkevan]

Still have a first-generation iPod Touch running iOS 3. Works like a charm, can even download some apps from the App Store. Bit of a shock how both primitive and advanced the early versions of iOS were.

[jmnicolas]

I had an iPad 1 running iOS 5 I think, but in the end I stopped using it because Safari would "crash" on most websites due to it running out of ram I guess.

IIRC there's 128M of ram on the fist iPad.