Convoy tiny (SS)
Olight I3E Eos
Jetbeam Jet-U
Maglite Solitaire
I have the above 4 single AAA lights and like them all for completely different reasons, but my Nitecore Tip SS is on my keyring for the foreseeable future, awesome light.
The Jetbeam Jet-U is the best single AAA of the bunch. I have an Astrolux Copper A-01 on the way as well for further comparison.
For the last couple of years, my keychain flashlight of choice has been my Olight silver 120 lumen i3E EOS. I like that it’s one mode, and the silver (probably chrome) finish has been almost scratch free even though it’s been rubbing up against keys all the time I’ve owned it.
The UltraTac K18 has been my go to keychain/pocket clip edc for quite a while now. Ended up with 2 of them, because they are fantastic either with a AAA or a 10440.