Aegis legend just over a year so far.
Had a pico for about 10 months, bought second hand and I believe it's well over 2 years old now.
Just got given another Pico from a member here that was once lost property, it's beat to buggery and was full of dirty crap - probably getting on for a couple of years old (it's a rev1 PCB). Working just fine (using it right now as it happens).
Oddly, the mod that had the highest price tag when new (squid db2.1) is the one I expect to fail the soonest.